Characterization and quantitative determination 
of aromatics, nitrogen, sulfur and trace metals in 
fuel and hydrocarbon samples 
 
 
by 
Vamshi Inumula 
 
 
Submitted in Partial Fulfillment of the Requirements 
 
for the Degree of 
 
 
Master of Science in Chemistry  
 
 
 
YOUNGSTOWN STATE UNIVERSITY 
 
August, 2013
 
 
 
 
 
Characterization and quantitative determination of aromatics, nitrogen, sulfur and trace 
metals in fuel and hydrocarbon samples 
 
Vamshi Inumula 
 
 
I hereby release this thesis to the public.  I understand that this thesis will be made 
available from the OhioLINK ETD Center and the Maag Library Circulation Desk for 
public access.  I also authorize the University or other individuals to make copies of this 
thesis as needed for scholarly research. 
 
 
 
 
 
Signature: 
     
  Vamshi Inumula, Student  Date 
 
 
 
 
 
Approvals: 
      
  Dr. Josef Blair Simeonsson, Thesis Advisor Date 
 
 
 
      
  Dr. Daryl W. Mincey, Committee Member Date 
 
 
   
 
      
  Dr. Ruigang Wang, Committee Member Date 
 
 
 
 
      
  Dr. Salvatore A. Sanders, Associate Dean of Graduate Studies Date
iii 
 
 
 
ABSTRACT 
High resolution two- dimensional gas chromatography time- of- flight mass 
spectrometry (GC x GC TOFMS), inductively coupled plasma mass spectrometry (ICP- 
MS) and trace nitrogen/ sulfur analysis methods are used to analyze the fuel and 
hydrocarbon liquid samples. The high resolution two- dimensional gas chromatography 
(GC x GC) along with one dimensional gas chromatography are used to separate the 
complex samples and to report the identification of separated components provided by 
time- of- flight mass spectrometer (TOFMS). Traces of elements in gasoline, diesel fuel, 
pygas samples are determined by inductively coupled plasma mass spectrometry (ICP- 
MS). A lithium metaborate fusion method was used for sample preparation. As nitrogen/ 
sulfur are present in smaller concentrations in gasoline, diesel fuel and pygas samples, 
accurate determination of these nitrogen/ sulfur concentrations is important for quality 
control, to prevent engine deposits and to meet the regulatory requirements. For this a 
nitrogen/ sulfur instrument with an automatic quick furnace is used for selective and 
sensitive measurements of these elements. 
 
 
 
 
 
iv 
 
 
Acknowledgement 
 I want to thank everyone, who helped me to present this thesis. My heart full 
gratitude to Dr. Josef Blair Simeonsson who always been encouraging and supportive. 
His cool attitude made this lab experience memorable. I would also like to acknowledge 
my committee members Dr. Daryl W. Mincey and Dr. Ruigang Wang whose 
encouragement and knowledge helped me to improve my understanding on the subject. I 
also express my sincere gratitude to Ray Hoff for his support with ICP-MS, GC x GC- 
TOFMS, Nitrogen/ Sulfur Analyzer. 
 I would like to thank my fellow students and friends Varun Sama, Sandeep K. 
Kakkerla. 
 I am indebted to my family, without whose love, support and patience none of this 
would be possible. I am always grateful to my mom, dad and brother who have been a 
constant source of love, support, concern and strength all these years. 
 I would also like to thank Chemistry Department for funding my project. Finally I 
would like to thank staff of Graduate School for their momentous help.  
 
 
 
 
 
 
v 
 
 
Table of Contents 
 
SIGNATURE PAGE ........................................................................................................... i 
ABSTRACT ....................................................................................................................... iii 
Acknowledgement ............................................................................................................. iv 
Table of Contents ................................................................................................................ v 
List of Figures ................................................................................................................... vii 
List of Tables ...................................................................................................................... x 
CHAPTER 1: Introduction ................................................................................................. 1 
1.1 Gasoline ..................................................................................................................... 3 
1.2 Gasoline blending ...................................................................................................... 3 
1.3 Physical and chemical properties of gasoline ........................................................... 6 
CHAPTER 2: Instrumentation .......................................................................................... 11 
2.1 GC x GC TOFMS ................................................................................................... 11 
2.2 Inductively coupled plasma mass spectrometry (ICP- MS) .................................... 33 
2.3 Nitrogen/ sulfur analyzer ......................................................................................... 37 
CHAPTER 3: Experimental section ................................................................................. 39 
3.1 GC x GC TOFMS ................................................................................................... 39 
3.2 Inductively coupled plasma mass spectrometry (ICP- MS) .................................... 45 
3.3 Nitrogen/ sulfur analyzer ......................................................................................... 48 
vi 
 
 
CHAPTER 4: Results and discussion ............................................................................... 50 
4.1 GC x GC TOFMS ................................................................................................... 50 
4.1.1 One dimensional gas chromatography ............................................................. 50 
4.1.2 Two dimensional gas chromatography ............................................................. 74 
4.1.3 Qualitative characterization and quantitation of gasoline, diesel fuel and pygas 
samples .................................................................................................................... 103 
4.2 Inductively Coupled Plasma Mass Spectrometry (ICP- MS) ................................ 133 
4.2.1 Elemental analysis of gasoline, diesel and pygas samples ............................. 135 
4.2.2 Elemental analysis of gasoline, diesel and pygas samples ............................. 136 
4.3 Nitrogen/ sulfur analyzer ....................................................................................... 139 
4.3.1 Nitrogen .......................................................................................................... 139 
4.3.2 Sulfur .............................................................................................................. 141 
4.4 Conclusion ............................................................................................................. 145 
References ....................................................................................................................... 147 
 
 
 
 
vii 
 
 
List of Figures 
Figure 1: Gas chromatograph............................................................................................ 12 
Figure 2: Typical van deemter plots for common carrier gases used in GC systems ....... 16 
Figure 3: Split less and split liner ..................................................................................... 18 
Figure 4: Ion source .......................................................................................................... 25 
Figure 5: Ions pushed from ion source ............................................................................. 26 
Figure 6: Ions acceleration ................................................................................................ 27 
Figure 7: Ions in drift region ............................................................................................. 27 
Figure 8: Ions mass/ charge ratio at detector .................................................................... 28 
Figure 9: GC x GC TOFMS instrument ........................................................................... 32 
Figure 10: Calibration curve of benzene ........................................................................... 51 
Figure 11: Calibration curve of toluene ............................................................................ 52 
Figure 12: Calibration curve of ethylbenzene ................................................................... 53 
Figure 13: Calibration curve of styrene ............................................................................ 54 
Figure 14: Calibration curve of cumene ........................................................................... 55 
Figure 15: Calibration curve of α- methylstyrene ............................................................. 56 
Figure 16: Calibration curve of benzene ........................................................................... 76 
Figure 17: Calibration curve of toluene ............................................................................ 77 
Figure 18: Calibration curve of ethylbenzene ................................................................... 78 
viii 
 
 
Figure 19: Calibration curve of styrene ............................................................................ 79 
Figure 20: Calibration curve of cumene ........................................................................... 80 
Figure 21: Calibration curve of α- methyl styrene ............................................................ 81 
Figure 22: Spectra of benzene in gasoline regular (130611) .......................................... 112 
Figure 23: 3D Image of gasoline super (130611) ........................................................... 113 
Figure 24: Total ion chromatogram of gasoline super (130611) .................................... 113 
Figure 25: 3D Image of diesel pilot (130611) ................................................................ 120 
Figure 26: Total ion chromatogram of diesel pilot (130611) ......................................... 120 
Figure 27: 3D Image of distillation standard D 86 ......................................................... 123 
Figure 28: Total ion chromatogram of distillation standard D 86 .................................. 123 
Figure 29: 3D Image of 130417 post scrub .................................................................... 131 
Figure 30: Total ion chromatogram of 130417 post scrub ............................................. 131 
Figure 31: Calibration curve of vanadium ...................................................................... 133 
Figure 32: Calibration curve of chromium ..................................................................... 134 
Figure 33: Calibration curve of cobalt ............................................................................ 134 
Figure 34: Calibration curve of lead ............................................................................... 135 
Figure 35: Calibration curve of nitrogen ........................................................................ 140 
Figure 36: Signal traces for samples containing different concentrations of nitrogen ... 141 
Figure 37: Calibration curve of sulfur ............................................................................ 142 
ix 
 
 
Figure 38: Signal traces for samples containing different concentrations of sulfur ....... 143 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
x 
 
 
List of Tables 
Table 1: Physical and chemical properties of gasoline ....................................................... 6 
Table 2- Major components of gasoline ............................................................................. 9 
Table 3: Column configuration ......................................................................................... 19 
Table 4: List of aromatics for standard calibration ........................................................... 39 
Table 5: Column configuration for GC oven .................................................................... 40 
Table 6: Experimental conditions ..................................................................................... 41 
Table 7: Stock solution ..................................................................................................... 42 
Table 8: Mass percent of aromatics in different calibration standards ............................. 43 
Table 9: Internal standards ................................................................................................ 44 
Table 10: Experimental conditions for nitrogen/ sulfur analyzer ..................................... 49 
Table 11: Limit of detection for aromatics in mass percent ............................................. 57 
Table 12: Quantified aromatics in D 86 in mass percent .................................................. 57 
Table 13: Quantified aromatics in gasoline super (130611) in mass percent ................... 58 
Table 14: Quantified aromatics in gasoline regular (130611) in mass percent ................ 59 
Table 15: Quantified aromatics in gasoline regular (130522) in mass percent ................ 60 
Table 16: Quantified aromatics in gasoline regular (130505) in mass percent ................ 61 
Table 17: Peak table of diesel collected on different days................................................ 62 
Table 18: Quantified aromatics in 130417 post scrub in mass percent ............................ 63 
xi 
 
 
Table 19: Quantified aromatics in 130313 post scrub in mass percent ............................ 63 
Table 20: Quantified aromatics in 130313 pyrogas scrub in mass percent ...................... 64 
Table 21: Quantified aromatics in hydro treated gasoline fraction in mass percent ......... 64 
Table 22: Quantified aromatics in 111005 Dr- 1 heated 2X in mass percent ................... 65 
Table 23: Equation of line and correlation coefficient of calibrated aromatics ................ 66 
Table 24: Limit of detection for aromatics in mass percent ............................................. 66 
Table 25: Quantified aromatics in distillation standard D 86 in mass percent ................. 67 
Table 26: Quantified aromatics in gasoline super (130611) in mass percent ................... 68 
Table 27: Quantified aromatics in gasoline regular (130611) in mass percent ................ 68 
Table 28: Quantified aromatics in gasoline regular (130522) in mass percent ................ 69 
Table 29: Quantified aromatics in gasoline regular (130505)  in mass percent ............... 69 
Table 30: Peak table of diesel collected on different days in mass percent ...................... 71 
Table 31: Quantified aromatics in 130417 post scrub in mass percent ............................ 72 
Table 32: Quantified aromatics in 130313 post scrub in mass percent ............................ 72 
Table 33: Quantified aromatics in 130313 pyrogas Scrub in mass percent ...................... 73 
Table 34: Quantified aromatics in hydro treated gasoline fraction in mass percent ......... 73 
Table 35: Quantified aromatics in 111005 Dr- 1 heated 2X in mass percent ................... 74 
Table 36: Limit of detection for aromatics in mass percent ............................................. 81 
Table 37: Quantified aromatics in distillation standard D 86 in mass percent ................. 82 
xii 
 
 
Table 38: Quantified aromatics in gasoline super (130611) in mass percent ................... 83 
Table 39: Quantified aromatics in gasoline regular (130611) in mass percent ................ 83 
Table 40: Quantified aromatics in gasoline regular (130522) in mass percent ................ 84 
Table 41: Quantified aromatics in gasoline regular (130505) in mass percent ................ 84 
Table 42: Quantified aromatics in diesel marathon (130611) in mass percent................. 85 
Table 43: Quantified aromatics in diesel pilot (130611) in mass percent ........................ 85 
Table 44: Quantified aromatics in diesel (130505) in mass percent ................................. 86 
Table 45: Quantified aromatics in 130417 post scrub in mass percent ............................ 87 
Table 46: Quantified aromatics in 130313 post scrub in mass percent ............................ 87 
Table 47: Quantified aromatics in 130313 pyrogas scrub in mass percent ...................... 88 
Table 48: Quantified aromatics in hydro treated gasoline fraction in mass percent ......... 88 
Table 49: Quantified aromatics in 111005 Dr- 1 heated 2X in mass percent ................... 89 
Table 50: Equation of Line and Correlation Coefficient for aromatic compounds .......... 90 
Table 51: Limit of detection for aromatics in mass percent ............................................. 90 
Table 52: Quantified aromatics in distillation standard D 86 in mass percent ................. 91 
Table 53: Quantified aromatics in gasoline super (130611) in mass percent ................... 92 
Table 54: Quantified aromatics in gasoline regular (130611) in mass percent ................ 92 
Table 55: Quantified aromatics in gasoline regular (130522) in mass percent ................ 93 
Table 56: Quantified aromatics in gasoline regular (130505) in mass percent ................ 93 
xiii 
 
 
Table 57: Quantified aromatics in diesel marathon (130611) in mass percent................. 94 
Table 58: Quantified aromatics in diesel pilot (130611) in mass percent ........................ 95 
Table 59: Quantified aromatics in diesel (130505) in mass percent ................................. 95 
Table 60: Quantified aromatics in 130417 post scrub in mass percent ............................ 96 
Table 61: Quantified aromatics in 130313 post scrub in mass percent ............................ 96 
Table 62: Quantified aromatics in 130313 pyrogas scrub in mass percent ...................... 97 
Table 63: Quantified aromatics in hydro treated gasoline fraction in mass percent ......... 97 
Table 64: Quantified aromatics in 111005 Dr- 1 heated 2X in mass percent ................... 98 
Table 65: 2D data for samples in mass percent ................................................................ 99 
Table 66: 2D data for samples in mass percent .............................................................. 100 
Table 67: 1D data for sample in mass percent ................................................................ 101 
Table 68: 1D data for all samples in mass percent ......................................................... 102 
Table 69: Peak table of gasoline super (130611) ............................................................ 104 
Table 70: Hit table of benzene in gasoline regular (130611) .......................................... 111 
Table 71: Peak table of diesel pilot (130611) ................................................................. 114 
Table 72: Peak table of distillation standard D 86 .......................................................... 121 
Table 73: Peak table of 130417 post scrub ..................................................................... 124 
Table 74: Elements in different grades of gasoline, diesel and pygas samples (PPM) .. 137 
Table 75: Nitrogen and sulfur concentrations in standards ............................................ 139 
xiv 
 
 
Table 76: Nitrogen and sulfur concentrations in gasoline, diesel and pygas samples 
(PPM) .............................................................................................................................. 144 
1 
 
 
CHAPTER 1: Introduction 
The determination of aromatic compounds in reformulated gasoline (RFG) is of 
importance to refiners because laws exist limiting the amount of emission of ozone 
forming and pollutant compounds [1]. The levels of aromatic compounds in gasoline are 
adjusted by refiners to comply with the environmental regulations and to improve the 
performance and properties of the fuels. 
The environmental protection agency (EPA) has established that the 
determination of benzene, toluene and total aromatics should be done by gas 
chromatography mass spectrometry (GC-MS) [2]. EPA has also certified that a fuel 
complies with the standards for RFG only if it contains a minimum of 2.0 mass percent 
oxygen and maximum volume percent benzene. The emission performance of a fuel is 
based on a complex model which requires the input of a number of fuel parameters 
(chemical composition and physical properties), each of which must be measured by a 
specific test method designated by the EPA [3]. Such input parameters include the 
chemical composition and total aromatic content of the fuel. Due to the complex 
hydrocarbon matrix of the fuel, it is difficult to chromatographically separate all aromatic 
compounds from other non- aromatic hydrocarbons. To ensure the consistent 
implementation of the EPA method, the American Society for Testing and Materials 
(ASTM) has developed a standard test method that meets the requirement of the EPA. 
This standard test method (D5769) is used for the determination of total aromatics in 
finished gasoline samples by Gas Chromatography Mass Spectrometry. In this study, the 
analysis of fuel and hydrocarbon samples is complicated by a relatively large number of 
2 
 
 
volatile components, and GC x GC TOFMS has been investigated for the complete 
aromatic analysis and characterization of these samples. 
The Pegasus 4D GC x GC TOFMS has several advantages over traditional GCMS 
systems. The Pegasus II provides a spectral collection rate up to 500 full- range mass 
spectra/ second to allow accurate measurement of the narrowest GC peaks. The analyte 
detectability can be increased by cryo- focusing the sample before separation by the 
secondary column. The automated peak find algorithm effectively locates the position of 
all the peaks in the chromatogram and reduces analysis time [4]. The unique features of 
the Pegasus II in fuel analysis were evaluated using a fast gas chromatographic method 
for rapid determination of total aromatics in finished gasoline [5]. 
Traces of elements in fuel and hydrocarbon samples are determined by 
inductively coupled plasma mass spectrometry (ICP- MS). A lithium metaborate fusion 
method for sample preparation and a standard multi- element calibration were used to 
quantify these samples.  
Nitrogen and sulfur compounds exist in a wide variety of analytical samples like 
petroleum refinery, and environmental samples. The determination of these compounds 
in complex samples like gasoline, diesel fuel, and pygas samples is important for quality 
control. Due to the complex nature of the fuel and hydrocarbon samples and the low 
concentrations, an element specific method for nitrogen/ sulfur is required. To meet this 
challenge, a nitrogen/ sulfur analyzer that uses oxidative combustion followed by 
chemiluminescence detection for nitrogen and UV fluorescence detection for sulfur was 
utilized. The nitrogen/ sulfur analyzer is an example of simultaneous nitrogen/ sulfur 
detection and is known for its selectivity and sensitivity. The main goal of these studies is 
3 
 
 
to prepare a series of calibration standards and then quantify the gasoline samples using 
the calibrated standards. 
1.1 Gasoline 
Gasoline is a refined product of petroleum consisting of a mixture of 
hydrocarbons, additives and blending agents. The composition of gasoline depends on the 
crude oils used, the refinery processes available, and the product specifications. Gasoline 
is primarily divided into regular, plus and premium according to the different octane 
number. Gasoline primarily comes from petroleum cuts with boiling points ranging from 
38
o
C to 150- 205
o
C and is blended with different components to improve the fuel 
properties. 
Different grades of gasoline (regular, plus and premium) are obtained through blending 
of light straight runs, catalytic reformates, hydrocracked gasoline, catalytically cracked 
gasoline, alkylates, n- butane and oxygenates like Methyl Tertiary Butyl Ether(MTBE) 
[6]. 
The elimination of lead from gasoline made the refiners rely mostly on Methanol, 
Ethanol, oxygenates like Di Methyl Ether [DME], Methyl Tert- Butyl Ether (MTBE), 
Ethyl Tertiary Butyl Ether [ETBE], and Tetra Amyl Methyl Ether [TAME] to achieve 
acceptable octane levels [7].  
1.2 Gasoline blending 
Streams of gasoline blends are refined from crude oil or petroleum. The 
hydrocarbon molecules in the crude oil range from one to 50 or more carbon atom. 
Petroleum refining in general is distillation as well as chemical treatment. Catalyst and 
4 
 
 
pressure are the two factors which separate the hydrocarbon molecules and combine them 
into petroleum streams for commercial petroleum products. Gasoline is blended from 
various petroleum refinery streams by direct distillation of crude oil, hydrocracking, 
catalytic and thermal cracking, catalytic reforming, alkylation and polymerization. 
Direct distillation of crude oil separates mixture of substances with a narrow 
difference in the boiling points and is one of the most important steps in the refining 
process. The crude oil contains various components having different sizes, weights and 
boiling temperatures. The components in the crude oil can be separated by fractional 
distillation because of different boiling temperatures. Hydrocracking is the process of 
catalytic cracking in the presence of elevated partial pressure of hydrogen which permits 
wide variations in the yields of gasoline by removing sulfur and nitrogen hetero- atoms. 
Hydrocracked stocks of gasoline lacks high octane olefin content present in catalytically 
cracked stocks, so they must be reformed [8]. The reforming process converts low octane 
olefins to higher octane liquid components in the gasoline. Catalytic reforming 
completely replaces thermal reforming. Most catalytic reforming catalysts contain 
platinum with another promoting metal such as rhenium [8, 9]. In gasoline refining, 
alkylation processes convert the refinery gases into gasoline range liquids, however this 
approach is expensive and not commonly used in gasoline production [8, 10].  
Polymerization is a process of reacting or combining two or more low molecular 
weight olefins into higher molecular weight olefin liquids for gasoline blending [8]. The 
polymerization process is no longer used to produce gasoline blend streams [8, 10]. With 
the elimination of lead phase in gasoline, different options for increasing the octane have 
been explored [11]. Refining and blending of fuel components produce a fuel with 
5 
 
 
increased knock resistance [12]. Oxygenates like MTBE, ETBE, and DME are also added 
to gasoline to increase the overall octane number and to improve combustion efficiency 
[13]. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
6 
 
 
1.3 Physical and chemical properties of gasoline 
Table 1: Physical and chemical properties of gasoline 
Property Information Reference 
Molecular weight 108
a 
Anonymous 1989 
Color 
Colorless to pale brown or 
pink 
Sax and Lewis 1989; 
Weiss 1986 
Physical state Liquid Sax and Lewis 1989 
Boiling point 
Initially, 39
0
C 
After 10% distilled, 60
0
C 
    
    
    
Budavari et al. 1989; 
OHM/TADS 1991; 
    
Density 0.7-0.8 g/cm
3 b 
IARC 1989 
Odor Gasoline odor Weiss 1986 
Odor threshold 0.025 ppm 
c 
Weiss 1986 
Solubility: 
Water at 20
0
C Insoluble 
OHM/TADS 1991; 
Sax and Lewis 1989 
7 
 
 
Property Information Reference 
Organic solvent 
Absolute alcohol, ether, 
chloroform, benzene 
Budavari et al. 1989; 
Sax and Lewis 1989 
 
 
 
 
 
Partition coefficients: 
Log K
ow 
2.13-4.87
 d 
Air Force 1989 
Log K
oc 
1.81-4.56
 d 
Air Force 1989 
Vapor pressure: 
At 60
0
C 465 mmHg Weiss 1986 
At 56
0
C 518 mmHg Weiss 1986 
At 51
0
C 593 mmHg Weiss 1986 
At 47
0
C 698mmHg Weiss 1986 
At 41
0
C 773mmHg Weiss 1986 
8 
 
 
Property Information Reference 
Henry’s law constant; at 
20
0
C 
4.8*10
-4
- 3.3 m
3
/ mol 
e 
Air Force 1989 
Auto ignition temperature 280-486
0
C 
NEPA 1986; 
Sax and Lewis 1989 
  
Flammability limits 1.4-7.4% Weiss 1986 
Explosive limits 1.3-6.0% 
Budavari et al. 1989; 
Sax and Lewis 1989 
 
a. Average molecular weight. 
b. Temperature not specify 
c. Not specified whether data for air or water 
d. ASTM has established guidelines on the compositions of gasoline that will permit 
satisfactory performance under a range of conditions. These guidelines define five 
volatility classes that vary by seasonal climatic changes. The values given for vapor 
pressure at the given temperatures are based on volatility classes 
e. Since data are not available for gasoline, ranges are given indicating different values 
for the individual components. 
9 
 
 
Table 2- Major components of gasoline 
Component Percentage 
 
Component 
 
 
  
 Other possible components 
C
5 
3.0 Octane enhancers 
C
6
 11.6 Methyl t-butyl ether(MTBE) 
C
7
 1.2 t-butyl alcohol(TBA) 
C
9
 0.7 Ethanol 
C
10- 
C
13
 0.8 Methanol 
Total of n-alkanes 17.3 Antioxidants 
Branched alkanes  N,Ndialkylphenylenediamine 
C
4
 2.2 2,6-dialkyl and 2,4,6- trialkylphenols 
C
5
 15.1 Butylated methyl, ethyl and dimethyl phenols 
C
6
 8.0 Triethyene tetramine 
 
C
7
 1.9 Metal deactivators 
C
8
 1.8 N,N-disalicylidene-1,2ethanediamine 
C
9
 2.1 N,N-disalicylidene-propanediamine 
C
10
 - C
13
 1.0 N,N-disalicylidene-cyclohexanediamine 
Total of branched 32.0 Disalicylidene-N-methyl-dipropylenetriamine 
Cyclo alkanes  Ignition controllers 
C
6
 3.0 Tri-o-cresylphosphate(TOCP) 
C
7
 1.4 Icing inhibitors 
C
8
 0.6 Isopropyl alcohol 
Total of cyclo 
 
5.0 Detergents/dispersants 
Olefins  Alkyl amine phosphates 
C
6
 1.8 Poly-isobutene amines 
Total of olefins 1.8 Long chain alkyl phenols 
Aromatics  Long chain alcohols 
Benzene 3.2 Long chain carboxylic acids 
Toluene 4.8 Long chain amines 
10 
 
 
Component Percentage 
 
Component 
Xylenes 6.6 Corrosion inhibitors 
Ethyl benzene 1.4 Carboxylic acids 
C
3
- benzene 4.2 Phosphoric acids 
C
4
- benzene 7.6 Sulfonic acids 
Others 2.7  
Total aromatics 30.5  
 
[a] Adapted from Air Force 1989 
[b] Percent by weight 
 
 
 
 
 
 
 
 
 
11 
 
 
CHAPTER 2: Instrumentation 
2.1 GC x GC TOFMS 
All the work has been performed on a PEGASUS 4D GC x GC TOFMS which 
has an Agilent Technologies 7890A GC system equipped with an Pegasus HT (High 
Throughput) TOFMS having a Micro channel plate detector. The auto sampler used is 
CTC Analytics Combi Pal System and the true signal deconvolution is done by Chroma 
TOF. 
Basic principle of GC x GC: 
GC x GC is an analytical technique that can be used to separate the volatile 
organic compounds in a gaseous mixture based on two different separation mechanisms. 
The Gas Chromatograph usually consists of two capillary columns with different 
stationary phases i.e., one in the main oven and the other in the secondary oven coupled 
in series. Between the two columns is a trapping and cooling device which is called the 
Thermal Modulator. 
A schematic overview of a GC x GC system is shown in Figure 1. 
12 
 
 
 
Figure 1: Gas chromatograph 
I= Injector  
M= Thermal Modulator 
D= Detector 
1
st
= 1
st
 dimension column 
2
nd
= Secondary Oven 
The first dimension column is a conventional GC- separation, with a normal GC-
column length in an oven that will be temperature programmed. The one dimensional 
(1D) chromatogram which is obtained in a conventional GC separation shows a 
chromatogram in which the x- axis represents the retention time and the y- axis represents 
the intensity. In the two-dimensional chromatogram, the x- axis represents the retention 
time of the separation on the first dimension column and the y-axis represents the 
retention time on the secondary oven. 
13 
 
 
Pegasus 4D GC x GC TOFMS instrumentation in this project consists of: 
1. Gas chromatograph 
A. Carrier gas 
B. Injector 
C. Capillary column 
D. Thermal modulator 
E. Secondary oven 
2. Transfer line 
3. Mass spectrometer 
A. Ion source 
B. Mass analysis 
C. Ion detection 
4. Data processing and peak deconvolution 
1. Gas chromatograph: 
A. Carrier gas: 
In gas chromatography, the carrier gas (mobile phase) that carries the analyte 
through the column should be light and inert. The most commonly used carrier gases or 
the mobile phase in GC x GC TOFMS are helium, hydrogen and nitrogen. In this work, 
helium is used as the carrier gas due to its inert nature. It is safer than hydrogen which 
can accumulate when the GC, mass spectrometer, or rough pump is shut down un-
14 
 
 
intentionally or due to an internal or external power failure. The low molecular weight 
of helium allows faster analyses than nitrogen. 
 Martin and Synge proposed that the higher diffusivities of solutes in gas would 
result in faster partitioning of the analytes between two phases, more efficient columns, 
and shorter separation times [14]. The work demonstrated that the gas could be used as a 
mobile phase and was further supported by the work of James and Martin in 1952. In this 
paper, the use of passing an inert gas through a steel column packed with activated 
carbon in order to separate a homologous series of fatty acids was discussed [15]. The 
work of Martin, Synge, and James was further developed by Van Deemter who is 
credited with the development of “rate theory” [16]. The theory incorporates both kinetic 
and mass transfer effects with the “plate theory” developed by Craig [17]. Van Deemter 
proposed that the broadening of chromatographic peaks traveling through a column is 
dependent upon three factors: eddy diffusion (A- term), longitudinal diffusion (B- term), 
and the resistance to mass transfer (C- term) [16]. It should be noted that the resistance to 
mass transfer term includes the resistance to mass transfer in the stationary phase, C
s 
and 
in the mobile phase, C
m
. Equation 1 shows the standard and extended forms of the van 
Deemter equation relating these three factors to the plate height H, and the average linear 
velocity 𝜇̅. 
𝐻 = 2𝜆𝑑
𝑝
+
2𝛾𝐷
𝑚
µ�
+ �
𝜔𝑑
𝑐
2
𝜇�
𝐷
𝑚
+  
𝑅𝑑
𝑓 
2
𝜇�
𝐷
𝑠
� = 𝐴 + 
𝐵
𝜇�
+ (𝐶
𝑠
+ 𝐶
𝑚
)𝜇̅    …………….Equation 1 
 
 
 
15 
 
 
In the above equation 
2𝜆𝑑
𝑝
,
2𝛾𝐷
𝑚
µ�
,
𝜔𝑑
𝑐
2
𝜇̅
𝐷
𝑚
,
𝑅𝑑
𝑓 
2
𝜇̅
𝐷
𝑠
 𝑐𝑜𝑟𝑟𝑒𝑠𝑝𝑜𝑛𝑑 𝑡𝑜 𝑡ℎ𝑒 𝐴,
𝐵
𝜇̅
,𝐶
𝑠
 𝑎𝑛𝑑 𝐶
𝑚 
𝑡𝑒𝑟𝑚𝑠 
A= Eddy diffusion 
𝐵
𝜇�
 = longitudinal diffusion/ average linear velocity 
C
s
= Resistance to mass transfer in the stationary phase 
C
m
= Resistance to mass transfer in the mobile phase 
A graphical representation of the Van Deemter equation is shown in Figure 2 for 
nitrogen, helium, and hydrogen. The optimal linear velocity of the column is located at 
the lowest point on the curve which often corresponds to the point at which each of the 
three factors are minimized [16, 18]. 
16 
 
 
 
Figure 2: Typical van deemter plots for common carrier gases used in GC systems 
B. Injector: 
Sample introduction in gas chromatography is critical, in quantitative analysis 
since the amount of sample lost during the process is dependent on the sample 
introduction method. In this work, the sample is introduced by an auto sampler because 
of its better precision and accuracy when compared to that of manual sample injection. 
Types of injection: split and splitless 
The most common type of inlet system used in GC x GC is a split/ splitless inlet. 
A schematic diagram of the split/ splitless inlet system is shown in the figure 3. The 
purge valve attached to the inlet determines the type of injection whether it is split/ 
splitless. In a split injection, the purge valve opens allowing only a small fraction of the 
sample to be injected onto the capillary column. The split injections prevent the 
nonvolatile components or other contaminants from reading the capillary column and 
17 
 
 
produce sharp and narrow peaks [19- 21]. The main disadvantage is that it is less accurate 
than splitless injection for quantitation studies. The amount of sample that enters the 
capillary column is determined by the split ratio which is set by the user and is defined by 
the equation: 
Split ratio = (S + C) / C 
Where: 
S= flow rate at the splitter vent 
C= flow rate at the column outlet 
In a splitless injection, the analyte sample that is vaporized goes into the capillary 
column and this type of injection is preferred in trace analysis where the sample contains 
very small amount of analyte. Figure 3 shows typical glass liners that are often used for 
splitless and split injections, respectively. In splitless injections, the glass liner doesn’t 
contain any obstructions thereby allowing all the sample components into the column. In 
splitless injection, only the pure samples or solvent less samples are analyzed to prevent 
the damage to the capillary column. In split injections, a piece of glass wool in the glass 
liner traps the nonvolatile components and prevents them from entering into the capillary 
column [21, 22]. 
18 
 
 
 
Figure 3: Split less and split liner 
Heart cutting vs. comprehensive two dimensional GC: 
The main difference between heart cutting and comprehensive two dimensional 
GC is the amount of sample or the effluent that is separated on the secondary column. In 
heart cutting, only selected portion of the effluent is analyzed on the secondary column. 
As opposed to heart cutting, in the comprehensive GC x GC all the effluent from the 
primary column passes through the secondary column. In other words in the 
comprehensive technique, the entire sample is separated on both the primary and the 
secondary columns. 
C. Capillary column: 
The sample that is injected into a heated injection port, gets vaporized, and carried 
into a capillary column by a carrier gas such as helium or hydrogen. 
 
 
19 
 
 
Column dimensions and stationary phase: 
The columns used for a GC x GC TOFMS generally can vary in the length, 
internal diameters, and film thickness of the stationary phase. In general, the dimensions 
of the first column are typical of a column that is normally used with a single column GC 
or GC- MS system. The dimensions of the secondary column are usually much smaller. 
The second column usually has a length of 1- 2 meters and the internal diameter is about 
half the size of the first column [24- 28]. The main purpose of this secondary column is to 
perform a fast separation of compounds in the effluent from the primary column using a 
more polar stationary phase on the secondary column [24- 28]. A typical column set-up is 
that the primary column contains a polar stationary phase which separates the analytes 
based on polarity and the second column which separates the compounds based on their 
boiling points [23- 28]. 
 
Table 3: Column configuration 
S. No Type Location 
Length
(M) 
Internal 
Diameter(µ) 
Film 
Thickness
 
Maximum 
Temperature
 
1 Capillary GC Oven 10.000 180 0.20 340 
2 Capillary Secondary 
 
0.790 100 0.10 320 
3 Capillary Transfer Line 0.210 100 0.10 320 
 
In this work the capillary column used is a fused silica tube that is 10 m with a 
protective polyamide coating on the outside of surface for mechanical protection and the 
inner surface of the capillary column is coated with a specially formulated stationary 
phase. In this capillary column, the separation of the components of the mixture is done 
20 
 
 
with respect to time by their different migration rates through the column. Interaction of 
the sample molecules with the stationary phase as they move through the capillary 
column results in the retention of the sample molecules in the stationary phase and the 
duration of the retention depends on the type of analyte molecules, type of stationary 
phase, column temperature, flow rate and the type of carrier gas. The separation occurs 
through multiple events of retention and desorption during sample movement through the 
column in the carrier gas stream where the degree of this separation determines the 
chromatographic resolution. 
Press fit connector: 
             The primary column and the secondary column are connected by a connector 
called the press fit which is made up of a fused silica tube which provides an inert 
pathway as the sample passes from primary to secondary column. The press fit is prone to 
leaks which may be due to uneven cuts of the column, or the use of a capillary column 
having a larger internal diameter than the primary column. In GC x GC TOFMS, the only 
way to the seal of the press fit is by performing a leak test for air on the instrument [27]. 
D. Thermal modulator and its functions: 
              The modulator serves to allow the chromatographic peak that elutes or emerges 
from the end of the primary column to be time-sampled into the second column. The 
modulator is often referred to as the heart of the GC x GC, since it is the one which 
generates the second dimension separation of the sample. There are several modulators 
available in the market for GC x GC systems and the most commonly used modulators 
are the Deans switch, thermal sweeper and the thermal modulator. The thermal modulator 
uses alternating jets of cold and hot nitrogen gas to perform peak modulation in a two 
21 
 
 
stage process [27]. The two cold jets focus the fraction of eluent to narrow the bandwidth 
which ultimately split the narrow peak forming slices of eluent fraction. The two hot jets 
keep the fraction of eluent moving through the modulator making the process continuous 
as well as preventing interference between the fractions.  The nitrogen gas for the 
modulator is cooled by liquid nitrogen which enters the instrument from a small Dewar 
attached to the side of the GC oven. The Dewar is directly attached to a tank of liquid 
nitrogen. The flow of the liquid nitrogen into the Dewar is controlled by the data 
acquisition software or by the user [27]. In a thermal modulator, the length of time for the 
hot jacket is slightly shorter than that of the cold jacket and this time is determined by the 
modulation period which is controlled by the system software. This is critical for 
effective separation and for reducing the bandwidth of the sample. The software allows 
the user to change the modulation temperature, modulation period, and the time for the 
hot and cold jets. The modulator is also used to manipulate the retention of analytes on 
the second column by changing the modulation period and the pulse time for the two hot 
nitrogen jets in the modulator [27]. The modulation period depends on the complexity of 
the sample. The sample with the less complex mixture requires short modulation period 
and vice- versa. The final parameter of the thermal modulator that can be changed is its 
temperature which should be higher than the initial temperature of the secondary oven. 
However the modulator temperature does not interfere with the peak modulation process 
or the secondary column separation. The main reason behind the increase in modulator 
temperature is to reduce the overload of the sample on the secondary column. 
Specifications for thermal modulator: 
LN
2 
modulator: Liquid nitrogen 
22 
 
 
Consumable- free Modulator: Immersion cooler 
Minimum temperature: GC oven temperature + 3
o
C above the GC oven temperature 
For ambient- cooled GC ovens typical +30
o
C 
Maximum temperature: 400
o
C 
Maximum heating rate:  40
o
C per minute 
LN
2 
modulator cold jet flow, gas pressure: ~6 Ipm/ 15 psi (1.03 bar), dry nitrogen (dew 
point < -50
o
C) with periodic defrosting as needed 
Consumable free modulator cold jet flow, gas pressure: ~10 Ipm/ 15 psi (1.03 bar), dry 
air (dewPoint < -50
o
C) with periodic defrosting as needed 
Hot jet low, gas pressure: ~20 Ipm/ 30 psi (2.03 bars), dry air 
Modulation period: 1- 65 sec 
Hot pulse: minimum, 100 ms; 400 ms typical 
E. Secondary oven: 
                 The secondary oven is mainly used to optimize of the second dimension 
chromatographic separation. The dimensions of secondary column in the secondary over 
are small in terms of the length or internal diameter when compared to that of primary 
column and result in higher linear velocities for analytes moving through this column. 
The main purpose of the second column is to perform rapid separation of the eluent from 
the primary column using a more polar stationary phase on the second column resulting a 
thorough separation of the volatile analytes [24- 28]. 
Specifications for the secondary oven: 
23 
 
 
Minimum temperature: GC oven temperature +5
o
C, above ambient temperature 
Maximum temperature: 400
o
C
 
Heating rate, maximum: 40
o
C per minute 
Cooling gas, flow pressure: Air, ~ 40 Lpm/ 30 psi (2.07 bar) 
2. Transfer line: 
                  After the sample has been separated on both columns, it passes through a 
heated transfer line that serves to transfer the sample from the gas chromatograph to the 
mass spectrometer and also ensures that the sample remains in the gas phase when 
entering the ion source of the mass spectrometer [29- 31]. The temperature of the transfer 
line depends on the type of analyte in the sample and the temperature of the transfer line 
should be high enough to keep the sample in the vapor state, but low enough not to 
degrade any analyte in the sample. 
3. Mass spectrometer: 
                  In the mass spectrometer, the volatile analytes that is separated in the gas 
chromatograph are ionized, fragmented, analyzed, and identified based on their 
fragmentation pattern. A typical mass spectrometer has three main parts: the ion source, 
mass analyzer and the detector. The mass analyzer defines the sensitivity, resolution, and 
speed of the mass spectrometer. Common types of mass analyzers include double 
focusing, ion traps, quadrupoles, and time-of-flight analyzers. During this work, a time-
of-flight mass analyzer is used. 
A. Ion source: 
24 
 
 
                The main purpose of the ion source is to ionize and fragment the analyte in a 
given sample [30, 31]. The commonly used ionization in gas chromatography- mass 
spectrometry is Electron Impact Ionization (EI) and Chemical Ionization (CI). Electron 
Impact Ionization removes a valence electron from the atom with lowest ionization 
energy by bombarding the molecules with a beam of electrons resulting in the formation 
of a typically unstable radical- cation that undergoes rearrangement and/ or fragmentation 
[31, 32]. These mass fragments are unique and produce a characteristic mass spectrum 
for the analyte. In this work, only the electron impact ionization is used. The ion source 
usually has a heating block, filament and a repeller as shown in figure 4. The heating 
block maintains the analyte in the vapor state by maintain a constant temperature. The 
filament is generally held at 70 eV and generates high energy electrons capable of 
removing the valence electrons from the analyte. The analyte molecules fragment 
according to their structure and the type of functional groups present [32]. The 
fragmentation pattern (relative amount vs. mass/ charge ratio) is called a mass spectrum 
and is often unique to the molecule. The fragments in the ion source are pushed through a 
small opening to the mass analyzer by the repeller and the main purpose of the pumps is 
to remove the carrier gas, neutral and the negatively charged ions from the MS system 
and to slow down the analyte ions during fragmentation in the ion source. 
 
 
 
 
25 
 
 
 
 
 
 
 
 
 
 
Figure 4: Ion source 
B. Mass analyzer: 
 In this work, a time of flight mass analyzer is used. In general a time of flight 
systems are known for their high sensitivity, high resolution, and faster scan rates. In a 
time- of- flight mass spectrometer, the mass/ charge ratio of an ion is determined by 
measuring its travel time through the instrument starting from the ion source to the 
detector. All ions have the same kinetic energy. So the ion travels are proportional to 
their mass/ charge ratio. The smaller the ion, the faster its time- of- flight. Ions produced 
in the ion source are pushed out of it by applying an electrical pulse to the push pulse 
electrode as displayed in figure 6. The electrical force is created due to the difference in 
the electrical potential between the accelerating electron grid and push pulse electrode 
accelerates the positively charged ions into the flight tube. All of the ions having the 
same kinetic energy accelerate almost simultaneously and leave the ion source as 
displayed in figure 8. The ions from the ion source enter into a drift region where they 
      Magnet 
Repellar 
            Push Pulse Electrode 
                            Filament 
 Focusing Electrode 
  Acceleratory Electrode   
Extraction Electrode 
     Drift Region Electrode 
26 
 
 
have a constant energy as displayed in figure 8. Since all the ions have the same kinetic 
energy, their mass- to charge ratio determines their velocity as shown in figure 9. For 
ions having the same m/z ratio but moving with different velocities, the ions travelling 
with higher velocity reach the positively charged reflectron and move deep farther into it 
compared to ions with lower velocity. All ions of the same m/z reach the detector at the 
same time. 
 
 
 
 
 
 
 
Figure 5: Ions pushed from ion source 
 
 
 
 
 
 
 
 
 
Acceleratory           
Electrode   
    Drift Region Electrode 
         Detector 
 
 
 
 
       Ion Source 
Push Pulse                   
Electrode 
27 
 
 
 
 
 
 
 
 
 
Figure 6: Ions acceleration 
 
 
 
 
 
 
 
Figure 7: Ions in drift region 
 
 
 
 
Acceleratory           
Electrode   
    Drift Region Electrode 
         Detector 
 
 
 
 
       Ion Source 
Push Pulse                   
Electrode 
Acceleratory           
Electrode   
    Drift Region Electrode 
         Detector 
 
 
 
 
       Ion Source 
Push Pulse                   
Electrode 
28 
 
 
 
 
 
 
 
 
 
Figure 8: Ions mass/ charge ratio at detector 
                  Ideally, all the ions pulsed from the ion source should have the same kinetic 
energy, but they actually have a range of kinetic energies depending on several factors. 
This causes differences in the time- of- flight even for ions having the same mass/ charge 
ratio and reduces the mass resolution of the mass spectrometer. In order to reduce these 
differences and improve the mass resolution, an electrostatic device called a reflectron/ 
ion mirror is placed in the drift region. One advantage of the reflectron is that it reduces 
the overall size of the mass spectrometer as shown in figure 9. 
The mass/ charge ratio of each ion is determined by the equation 
t= slope*�𝑚/𝑧+ Offset 
Slope and offset values are constant and are specific to a particular mass 
spectrometer for a given set of parameter values. The slope and offset values are 
determined using a mass calibration standard. This mass calibration standard is done 
automatically by the chromaTOF software. During the determination of the slope and 
Acceleratory           
Electrode   
    Drift Region Electrode 
         Detector 
 
 
 
 
       Ion Source 
Push Pulse                   
Electrode 
29 
 
 
offset, the valve connecting the ion source chamber to the vial with a calibration 
compound, PFTBA is opened. The vapors of the PFTBA are introduced into the ion 
source and a mass spectrum is obtained. Since the mass calibration of PFTBA is known, 
the time- of- flight of each mass is measured. These measured values are then used to 
calculate the slope and offset values automatically by solving a set of linear equations by 
the chromaTOF software. 
           Since the probability of creating multiple charged ions by electron impact 
ionization with electrons of 70 eV energy, is low, almost all of the ions created are singly 
charged (z=1). Thus, the m/z values calculated from the time-of-flight equation give the 
masses of the ions directly. The time-of-flight is measured as the time between the 
moment when the push pulse is triggered and the moment when the signal maximum 
from the corresponding ion packet is detected. The time-of-flight of the heaviest ion 
possible for detection (m/z=1000) is approximately 170 μsec. This is the time required to 
acquire the complete mass spectrum of the sample ionized in the ion source. In addition, 
the complete mass spectrum is obtained by sampling all ions in the ion source 
simultaneously. These two important features, simultaneous sampling of all ions for each 
mass spectrum and a very short acquisition time for the mass spectrum, are the main 
advantages of that Time- of- Flight Mass Spectrometry. 
Vacuum system: 
                     Ions travel a long distance of more than one meter in the TOFMS. In order 
to survive during this period of travel to the detector, the ions must travel in a vacuum. 
To avoid ion loss due to scattering, or reactions, the average ion path until collision with 
a residual gas molecule, l (the mean free path), has to be much longer than the travel 
30 
 
 
distance L, shown as l>>L. This determines what vacuum level is required for the 
operation of the mass spectrometer. Optimal performance is achieved at residual gas 
pressure below 10
-6
Torr. The pressure of the vacuum is kept at 10
-7 
torr for a time- of- 
flight mass spectrometer by two turbo molecular pumps. 
                    The mass spectrometer is enclosed within a vacuum chamber and consists of 
two parts, the Ion Source Chamber and the Analyzer Chamber. The vacuum pumping 
system includes two high performance turbo molecular vacuum pumps, rough pump and 
turbulent pump specifically suited for pumping out the carrier gases such as helium or 
hydrogen. These turbo molecular pumps are backed by a mechanical rotary vane vacuum 
pump. The pumping speed of the turbo molecular pumps corresponds with the desired 
maximum carrier gas flow rate. The residual gas pressure is measured by a hot cathode 
gauge attached to the main analysis chamber. 
C. Ion detection: 
The ion detector used in this work is a micro channel plate and is common for 
most mass spectrometer systems. Approximately one million small pores each with a 
diameter of 10 μm penetrate the glass body of the micro channel plate creating one 
million single channel electron multipliers. Ions striking the internal surface of these 
channels knock out several electrons from the channel surface due to an effect called ion-
electron emission. These created electrons, called secondary electrons, are accelerated by 
the electric field applied across the plate surfaces. Due to electron-electron emission, each 
of the accelerated secondary electrons has enough energy to knock out several electrons 
when it strikes the channel wall surface. This process is repeated many times creating an 
31 
 
 
avalanche of electrons. Thus, the signal from a single ion can be amplified, which makes 
it easier to detect ions and to electronically process the resulting signal. 
The amount of amplification, also known as the detector gain, depends on the 
detector voltage applied across the micro- channel plate and the condition of the surface 
of the micro- channels. The ability to generate electrons can change due to surface 
degradation, ion and electron collisions, and moisture adsorption. The degree and rate of 
degradation, depends on detector usage conditions. In order to prevent exposing the ion 
detector to the highly abundant ions created from the carrier gas and residual gas, all 
undesirable ions are deflected by applying an electrical pulse to a set of deflection plates, 
located after the ion source. The electrical pulse has an appropriate delay and duration 
after each sampling of the ion source. 
4. Data processing and peak deconvolution: 
Peak deconvolution and data processing are the final points in mass spectrometer 
system to locate a specific mass/ charge ratio in the TIC (Total Ion Chromatogram). 
ChromaTOF has a peak deconvolution algorithm built in the data processing software 
making it possible to input multiple masses producing multiple EICs (Extracted Ion 
Chromatogram) on a single chromatogram. Due to the higher sensitivity of TOFMS 
system, the software produces EIC’s with high S/N ratio, has a high mass spectral 
acquisition rate up to 500 Hz, and stable baseline spectra. In general the data processing 
for the acquired samples can be processed immediately or at a later time. 
 
32 
 
 
 
Figure 9: GC x GC TOFMS instrument 
1. Sampling Inlet                            10. electron focusing optics 
2. Main Oven                            11. push pulse plate 
3. 1
st 
Dimension capillary column       12. Turbo molecular pump 
4. Thermal modulator         13. Ion focusing optics 
5. Secondary oven                   14. Z- steering and deflection plates 
6. 2
nd
 Dimension capillary column       15. Einzel lens and Y- steering plates 
7. Heated transfer line                       16. Reflectron 
8, 9. Main analysis chamber                 17. Detector 
33 
 
 
2.2 Inductively coupled plasma mass spectrometry (ICP- MS) 
Principle: 
The principle of ICP- MS is that the sample or analyte gets ionized by the application 
of high temperature plasma. These ionized atoms are then separated and identified 
according to their m/z (mass to charge ratio). A typical ICP- MS system consists of five 
sections: 
1. Automated sample introduction system 
2. Inductively coupled plasma (ICP) 
3. Interface 
4. Mass spectrometry 
5. Data processing and display system 
1. Automated sample introduction system: 
The most common type of sample introduction is when the liquid sample is forced 
into a pneumatic nebulizer by a peristaltic pump. This pneumatic nebulizer converts the 
liquid sample into an aerosol, which is transferred to a spray chamber from which the 
aerosol is carried by a stream of argon gas to the plasma through the spray chamber. 
2. Inductively coupled plasma: 
Plasma which is a partially ionized gas with sufficiently high temperature atomizes 
and ionizes most of the elements in the periodic table and argon is used as a carrier gas 
since it produces pure form of ions because of its inert nature. 
 
 
34 
 
 
The following are the types of ionization processes that occur in the ICP: 
M
 
+ A
+
              M
+ 
+ A
+ 
+ e
- 
 (ion- atom collision) 
M
 
+ A                M
+ 
+ A
 
+ e
- 
 (atom- atom collision) 
M
 
+ e
-
               M
+ 
+ 2e
- 
 (electron impact) 
Ar
+ 
+ X             Ar + X
+
 (charge transfer) 
Ar
m 
+ X             Ar + X
+
 + e
- 
(penning ionization) 
Penning ionization happens when a meta- stable atom collide with a neutral atom 
and ionizes the neutral atom by the de- excitation of the meta- stable atom. In ICP, the 
plasma torch consists of three concentric silica quartz tubes each of which is open at the 
top. 
      A RF induction coil is wrapped around the top opening of the silica quartz tube. 
Auxiliary argon passes through the central tube and argon gas is passed through the 
middle or second tube. The sample in the form of dried aerosol passes through the central 
tube by argon carrier gas. The helical flow pattern of the argon plasma gas isolates the 
outer most quartz tube from the plasma. Ionization of argon gas is done by a spark from a 
tesla coil probe. These seeded free electrons absorb enough energy from the coil and 
maintain constant temperature of the plasma 6000- 10000K. Accelerated electrons collide 
with the atoms and transfer their energy to the entire gas. Coolant gas passes through the 
outer tube and protects the quartz torch from overheating. Ions produced in the plasma 
enter the mass spectrometer through the interface. 
 
35 
 
 
3. Interface: 
The interface transfers the ions from the extremely hot plasma into the mass 
spectrometer. The mass spectrometer requires high vacuum to avoid the collisions 
between ions and with the gas molecules which diverts the ions from their trajectory. 
Also the mass spectrometer does not work at high temperatures. The temperature is 
reduced by a series of vacuum chambers held at low pressure. A water cooled nickel 
sampling cone with one mm diameter orifice is used to introduce gases into the mass 
spectrometer. A fraction of the plasma along with the analyte passes through the orifice 
and because of high vacuum pressure a gas expansion is formed which might take a form 
of a cone. Just behind this sample cone, another water cooled cone called a skimmer cone 
is placed with a small orifice. The ions passes through this skimmer as an ion beam into 
the mass spectrometer where the ions are separated according to their mass/ charge ratio. 
Several mass spectrometers are available for mass analysis but in this study, an iCAP Qc 
ICP MS, Thermo Scientific with a quadrupole mass filter is used. 
4. Quadrupole mass spectrometer: 
Quadrupole consists of four parallel rods where opposite rods are connected to 
radiofrequency and direct current which creates an electric field. The electric field in the 
quadrupole deflects or transmits ions of different masses. Only specified ions of same 
mass to charge are passed through the quadrupole and transferred to the ion detector. All 
other ions collide with the rods and are removed before reaching the detector. The 
detector then transfers the ion information to the data processor. 
 
36 
 
 
5. Data processing and display System: 
The detector transfers the ion information to system control for data processing. 
Experiment controller software system converts the signals into graphical display with 
real time data. The software can not only detect all the elements in the periodic table but 
also their isotope and isobars. 
 
 
 
 
 
 
 
 
 
 
 
 
 
37 
 
 
2.3 Nitrogen/ sulfur analyzer [34, 35] 
Principle: 
            The sample is introduced by a sample boat into furnace where it gets vaporized 
and carried by argon gas to a high temperature zone where it reacts with oxygen and gets 
converted to nitric oxide (NO). This NO reacts with ozone (O
3
) and is converted to 
excited nitrogen dioxide (NO
2
*
). The light emitted by this excited nitrogen dioxide when 
it decays is measured by a photo multiplier tube (PMT). 
            For sulfur, the sample is introduced by an automatic boat controller into furnace 
where it gets vaporized and carried to a high temperature zone where it is oxidized by 
oxygen and converted to sulfur dioxide which is then irradiated by ultraviolet rays to 
form excited sulfur dioxide (SO
2
*
). This excited sulfur dioxide returns to the ground state 
with the emission of photon energy. This emitted fluorescence is measured by a photo 
multiplier tube (PMT). 
Apparatus:  
Microliter Syringe: A microliter syringe with a constant rate injector system, capable of 
delivering 5- 250 µl is used to inject samples into sample boat.  
Sample inlet system: Direct injection and boat inlet system are the two types of sample 
inlet systems and the inlet system used with this instrument is a boat inlet system which 
facilitates analysis of samples that would react with the syringe needle. The boat inlet 
external to the furnace cools to room temperature to dissipate the heat from the boat when 
it is removed from the furnace. The boat is constructed of quartz. 
38 
 
 
Furnace: The electric furnace is maintained at a temperature (900- 1000
o
C) sufficient to 
pyrolyze and combust the sample and oxidize sulfur to sulfur dioxide (SO
2
) and 
organically bound nitrogen to nitric oxide (NO). 
Combustion tube: A quartz combustion tube is used so that the inlet end of the tube is 
large enough to accommodate the sample boat. 
Drier tube: The apparatus is equipped with a drier for the removal of water vapor 
produced during the oxidation reactions. The water vapor must be eliminated prior to the 
measurement by the chemiluminescence detector. 
 Chemiluminescent detector measures the light emitted from the 
reaction between nitrous oxide and ozone and the UV fluorescence detector measures the 
light emitted from the fluorescence of sulfur dioxide by UV light. 
Vacuum system: The chemiluminescence detector is equipped with a vacuum system to 
maintain the reaction cell at reduced pressure (typically at 20- 25 mm hg) which 
improves the signal to noise ratio of the detector. 
 
 
 
 
 
 
39 
 
 
CHAPTER 3: Experimental section 
Chemicals used: 
3.1 GC x GC TOFMS: 
The following aromatic compounds were analyzed: benzene, toluene, 
ethylbenzene, styrene, α- methylstyrene and cumene. 
Table 4: List of aromatics for standard calibration 
Aromatic compound Purity Supplier 
Benzene 99.9 % J. T. Baker 
Toluene 99.97 % Pharmco Aaper 
Ethylbenzene 99.9 % Fisher Scientific 
Styrene 99 % Sigma Aldrich 
α- Methylstyrene 99 % Aldrich 
Cumene 98 % Aldrich 
 
All the reagents used in this study were of analytical grade or better. Calibration 
standards were freshly prepared by appropriate dilutions of the stock with 2, 2, and 4- 
trimethylpentane (Isooctane). The reagents that were used for GC x GC TOFMS are as 
follows: 2, 2, 4- trimethylpentane (Sigma Aldrich- Reagent grade ACS), ethanol (Fisher 
Scientific- 0.2 µ filtered), and methanol (Fisher Scientific- 0.2 µ filtered). 
 
40 
 
 
GC x GC TOF Analysis 
All analysis was performed on an Agilent Technologies 7890A GC system 
equipped with a Pegasus HT High Throughput TOFMS. The GC was fitted with a 
capillary split/ splitless injection port. The mass spectrometer was fitted with Agilent 
Technologies high vacuum turbo pump V551 navigator. The auto- sampler used for this 
instrument is CTC Analytics CombiPAL System with a 10 µL syringe. 
Table 5: Column configuration for GC oven 
Type Location 
Length 
(m) 
Internal 
diameter 
 
Max 
Temp     
 
 
Film 
thickness 
 
Phase 
Bleed 
masses 
Inlet Front       
Capillary GC Oven 10.00 180.00 340.0 0.2 RTX- 5 74, 
 
 
Capillary Secondary 
 
0.570 100.00 320.0 0.1 RXI- 17 74, 
 
 
Capillary Transfer 
 
0.210 100.00 320.0 0.1 RXI- 17 74, 
 
 
Detector TOF       
 
 
 
 
 
 
 
 
41 
 
 
Table 6: Experimental conditions 
Component Condition 
GC  
Type Agilent 7890A system equipped with a 
      
Carrier gas Helium at 1.00 ml/ min constant flow 
Injection size 0.1 µL using a 1.2 µL syringe 
Split ratio 500:1 
Oven temperature programming 
10
o
C for 3 min, then to 100 
0
C at 10 
0
C/ 
min finally to 250 
0
C at 25
o
C/ min 
Modulation period(2D) 8.00 sec 
Hot pulse time (2D) 0.4 
Cool time between stages (2D) 3.6 
GC- MS Interface  
Interface Capillary direct 
Temperature 280
o
C 
Equilibrium time 1 sec 
MS  
Type Time- of- flight 
Acquisition voltage 1475 
Ion source temperature 200
o
C 
Storage mass range 5- 1000 U 
Acquisition rate 100 spectra/ sec
 
Ionization voltage 70 eV 
 
Sample preparation: 
Renewable energy solutions Polyflow (RES Polyflow): 
The RES Polyflow process is robust and is designed to handle the types and 
percentages of polymers present including plastic waste, tires and carpets as reported by 
42 
 
 
EPA. The RES Polyflows technology thermally decomposes hydrocarbon based materials 
such as plastic and rubber and converts them into organic compounds that can be 
marketed as transportation fuels and new feed stocks for new polymer production. The 
end product generated by the RES Polyflow is a liquid known as pygas from which diesel 
fuel, octane enhancers and gasoline blend stocks can be yielded. The main purpose of this 
work is to analyze these different pygas samples, diesel fuel, gasoline. 
Calibration curves: 
A 7 g stock aromatic mix was prepared by adding the seven aromatic compounds 
in decreasing order of their weights to a 10 mL volumetric flask. 
Table 7: Stock solution 
Compound Mass (g) Mass percent (%) 
Benzene 1.0 14.28 
Toluene 1.0 14.28 
Ethylbenzene 1.0 14.28 
Styrene 2.0 28.57 
α- Methylstyrene 1.0 14.28 
Cumene 1.0 14.28 
 
 This stock aromatic mix was diluted using serial dilution by isooctane to produce 
different calibration standards. A 1 % calibration standard was prepared by adding 0.21 g 
of stock solution to 2.79 g of isooctane. A 2 % calibration standard was prepared by 
adding 0.42 g of stock solution to 2.58 g of isooctane. A 3 % calibration standard was 
prepared by adding 0.63 g of stock solution to 2.37 g of isooctane. A 4% calibration 
standard was prepared by adding 0.84 g of stock solution to 2.16 g of isooctane. A 5% 
43 
 
 
calibration standard was prepared by adding 1.05 g of stock solution to 1.95 g of 
isooctane. The mass percent of aromatic compounds in different calibration standards are 
as follows: 
Table 8: Mass percent of aromatics in different calibration standards 
Compound 1%  2% 3% 4% 5% 
Benzene 1 2 3 4 5 
Toluene 1 2 3 4 5 
Ethylbenzene 1 2 3 4 5 
Styrene 2 4 6 8 10 
α- methylstyrene 1 2 3 4 5 
Cumene 1 2 3 4 5 
 
Internal standard: 
 For the reliable quantitative data, internal standards are required to correct the 
analytical and chemical losses during analysis. It was observed that the linearity with the 
benzene in calibrations standards was lost over a narrow concentration range and is not 
reproducible or the reproducibility is lost for the same set of calibration standards. This 
led to the conclusion that internal standards are needed which are structurally similar to 
that of the analytes and where the mass differences between the analytes and the internal 
standards are more than one mass unit. The deuterated components in the internal 
standard mix used for the analysis are shown in Table 9. 
 
 
44 
 
 
Table 9: Internal standards 
Component CAS number Purity % Weight 
   
 
 
Mix Ratio 
Benzene- d6 1076- 43- 3 97.1 16.70 2 ml 
Ethylbenzene- d8 25837- 05- 2 97 16.80 2 ml 
Naphthalene- d8 1146- 65- 2 100 8.84 1 g 
Toluene- d8 2037- 26- 5 98.2 57.66 7 ml 
 
Limit of detection (LOD): 
 The limit of detection or the detection limit (LOD) is the lowest quantity of a 
compound that can be distinguished from the absence of that compound. The calculation 
method is again based on the slope and the intercept of the calibration curve. 
S
y/x 
= [∑ (d
i
2
) / N-2]
1/2 
d
i 
= y
i 
- ( m * x
i
 + b) 
S
y/x 
= Limit of Detection 
d
i 
= residuals 
N = number of runs for each set of calibration standard 
m = slope from equation of line 
b = intercept from equation of line 
 The Carrier gas used for the GC x GC TOFMS is PRAXAIR BIP HE (Build In 
Purife Helium). PRAXAIR 22 PSI (cooling the oven) and 235 PSI (cold jets in 
Modulator) nitrogen refrigerated liquid are used. 
45 
 
 
3.2 Inductively coupled plasma mass spectrometry (ICP- MS) 
 The following elements were analyzed as per federal and state hazardous waste 
criteria: chromium, manganese, nickel, arsenic, selenium, silver, cadmium, mercury, lead, 
vanadium, cobalt, zinc and copper. All analysis was performed on iCAP Q ICP with a 
quadruple mass analyzer. All the standard solutions and samples were prepared using 
double distilled water. All the reagents used in this study were of analytical grade or 
better. Calibration standards were freshly prepared by appropriate dilutions of the stock 
with 3 % nitric acid. 
Sample and standard preparation: 
Gasoline and diesel samples: 
 Gasoline with super grade was obtained from Get GO Gas station. Diesel sample 
was obtained from two different places on different days. Gasoline with regular grade 
was obtained from the gas station on different days. All these samples were analyzed for 
chromium, manganese, nickel, arsenic, selenium, silver, cadmium, lead, vanadium, 
cobalt, zinc and copper on ICP- MS. 
Renewable energy solutions polyflow (RES Polyflow Samples): 
 The RES Polyflow process is robust and is designed to handle the types and 
percentages of polymers present including plastic waste, tires and carpets as reported by 
EPA. The pygas samples were collected from the reactor at different days and at different 
times and are named according to them. The main purpose of this work is to characterize 
these different pygas samples. All these samples were analyzed for chromium, 
46 
 
 
manganese, nickel, arsenic, selenium, silver, cadmium, mercury, lead, vanadium, cobalt, 
zinc and copper on ICP- MS. 
 Gasoline, diesel and Polyflow samples are acid digested or solubilized by lithium 
metaborate fusion before analysis. In general metals will not dissolve in organic solvents 
or regular solvent, and acid digestion is a method of dissolving the metal into solution 
which can then be analyzed to determine the amount of element or metal present in the 
sample. Organic sample materials present in the sample are generally decomposed into 
carbon dioxide with nitric acid and reagent hydrogen peroxide. 
Acid digestion procedure: 
A. Half a gram (solid) or One gram (liquid) of the sample is weighed into a teflon beaker 
B. Add 5 ml of nitric acid and 5 ml of water to the sample 
C. Gently heat the solution mixture, avoid spattering 
D. After about 5 min when the reaction slows down, add 2 ml of hydrogen peroxide 
E. When all but about 3- 4 ml of solution left, add more 5 ml of nitric acid and water 
F. After the reaction is complete, add 2 ml of hydrogen peroxide 
G. Drive off all but about 3 ml 
H. Cool, add 5 ml water and transfer to a 50 ml volumetric with distilled water. 
Lithium metaborate fusion method: 
A. Mix 0.1 g oven- dried sediment/ sample with 0.5 g lithium metaborate in a high purity 
graphite crucible 
B. Heat in a muffle furnace for 15 min at 1000 
0
C 
47 
 
 
C. Remove crucible and pour melt into polypropylene wide- mouth bottle containing 3 
% nitric acid 
D. Cap bottle and shake until solution is complete 
E. Add concentrated nitric acid in small (1 ml) aliquots to dissolve particulate/ turn 
solution clear if needed after shaking 
Standard preparation: 
A 10 ppm multi element analysis mixture was taken. An intermediate standard 
(500 ppb) was prepared to make a set of standards in parts per billion range. A 500 ppb 
calibration standard was prepared by adding 2.5 ml of 10 ppm multi- element standard 
diluting to 50 ml with distilled water. A  0.5 ppb, 1.0 ppb, 3.0 ppb, 10 ppb and 30 ppb 
calibration standards were prepared by adding 50 µL, 100 µL, 300 µL, 1 ml and 3 ml of 
intermediate standard (500 ppb) respectively and diluting to 50 ml with distilled water 
and a calibration standard was constructed using this set of standards. 
  
 
 
 
 
48 
 
 
3.3 Nitrogen/ sulfur analyzer 
 Nitrogen/ sulfur concentrations were analyzed on Mitsubishi Nitrogen/ sulfur 
analyzer which uses an oxidative combustion followed by chemiluminescence and 
fluorescence detection coupled with automatic boat controller (ABC 210) and automatic 
quick furnace (AQF 2100 H). All the reagents used in this study were of analytical grade 
or better. The reagents that were used for nitrogen sulfur determination are as follows: N, 
N- dimethylaniline (Acros organics), dibenzothiophene (Aldrich), toluene (Pharmco 
Aaper –UV reagent grade ACS). All the standard solutions and samples were prepared 
using toluene. Calibration standards were freshly prepared by appropriate dilutions of the 
stock with toluene. 
Standard preparation: 
 The stock solution for nitrogen sulfur determination is prepared based on mass by 
taking N, N- dimethyl aniline (0.1 g) and dibenzothiophene (0.1 g) in toluene (99.8 g) 
which is 1000 ppm. Calibration standards of 10 ppm, 50 ppm, 100 ppm, 300 ppm, 500 
ppm of N, N- dimethyl aniline and dibenzothiophene were prepared by adding 0.5 ml, 2.5 
ml, 5 ml, 15 ml, 25 ml of stock solution (1000 ppm) to a 50 ml volumetric flask 
respectively and finally diluting to 50 ml with toluene. 
Sample preparation: 
 All the gasoline and diesel fuel sample are directly analyzed for nitrogen/ sulfur 
content whereas the Polyflow samples are diluted to 1/ 10 in toluene. 
 
 
49 
 
 
Table 10: Experimental conditions for nitrogen/ sulfur analyzer 
Sample volume 25 µL 
Inlet heater temperature 900 
0
C 
Outlet heater temperature 1000 
0
C 
Argon flow 300 ml/ min 
Oxygen flow 300 ml/ min 
 
 The carrier gas used in nitrogen/ sulfur analyzer is PRAXAIR ultra-high pure 
compressed argon and oxygen with 99.993 % pure is used for combustion of the sample. 
 
 
 
 
 
 
 
50 
 
 
CHAPTER 4: Results and discussion 
4.1 GC x GC TOFMS 
4.1.1 One dimensional gas chromatography 
 Qualitative and quantitative analyses of all the gasoline, diesel fuel, Pygas 
samples and distillation standard, D 86 were performed by both one dimensional and two 
dimensional gas chromatography. All the samples were analyzed twice by both one 
dimensional and two dimensional gas chromatography to evaluate the method and to 
check the reproducibility of the results. 
4.1.1.1 Calibration of aromatic compounds (1D) 
Set 1: 
 A set of calibration standards of 1 %, 2 %, 3 %, 4 % and 5 %  each of benzene, 
toluene, ethylbenzene, cumene, α- methyl styrene and 2 %, 4 %, 6 %, 8 %  and 10 % of 
styrene is made to which  an internal standard is added. All the gasoline, diesel fuel, 
pygas samples and the distillation standard were taken into a 2.0 ml vial to which a 
known amount of internal standard is added and was qualitatively determined which is 
then quantified using the set 1 calibration standards. 
 In order to quantitatively determine the fuel and hydrocarbon samples, calibration 
curve measurements were performed and the typical calibration curves for benzene, 
toluene, ethylbenzene, styrene, cumene, α- methyl styrene are shown in figures 10 to 15. 
In the calibration curves, X- axis represents the concentration and the Y- axis represents 
the ratio of the area of analyte to that of internal standard 
51 
 
 
Benzene: 
 The calibration curve for benzene was constructed using the following 
concentrations: 1, 2, 3, 4, 5 %. Each standard was run in triplicate for  reproducibility of 
the results. The calibration curve for benzene is shown in figure 10 and the linearity is 
good with a correlation coefficient (R
2
= 0.99993). The internal standard used for benzene 
is benzene- d6 having a mass of 84+83 comes out at 72.77 sec. 
Name Mass Absolute R. T (Sec) Equation 
Correlation 
Coefficient 
Benzene 78 73.93 Y= +0.928628x + 0.0516181 0.99993 
 
 
Figure 10: Calibration curve of benzene 
 
 
1 2 3 4 5 6 7
1.00
1.50
2.00
2.50
3.00
3.50
4.00
4.50
Concentration
R
a
t
i
o
3% STD:1
1% STD:1
2% STD:1
4% STD:1
5% STD:1
y= +0.928628x + 0.0516181
r = 0.99993
52 
 
 
Toluene 
 The calibration curve for toluene was constructed using the following 
concentrations: 1, 2, 3, 4, 5%. Each standard was run in triplicate for  reproducibility of 
the results. The calibration curve for toluene is shown in figure 11 and the linearity is 
good with a correlation coefficient (R
2
= 0.99991). The internal standard used for toluene 
is toluene- d
8
 having a mass of 100 + 99 comes out at 186.32 sec. 
Name Mass 
Absolute R. T 
(Sec) 
Equation 
Correlation 
Coefficient 
Toluene 92 192.44 Y= + 0.283795x – 0.0148417 0.99991 
 
 
Figure 11: Calibration curve of toluene 
 
 
1 2 3 4 5 6 7
0.400
0.600
0.800
1.00
1.20
1.40
Concentration
R
a
t
i
o
3% STD:1
1% STD:1
2% STD:1
4% STD:1
5% STD:1
y= +0.283795x - 0.0148417
r = 0.99991
53 
 
 
Ethylbenzene: 
 The calibration curve for ethylbenzene was constructed using the following 
concentrations: 1, 2, 3, 4, 5%. Each standard was run in triplicate for  reproducibility of 
the results. The calibration curve for ethylbenzene is shown in figure 12 and the linearity 
is good with a correlation coefficient (R
2
= 0.99781). The internal standard used for 
ethylbenzene is ethylbenzene- d
8
 having a mass of 116 + 115 comes out at 324.64 sec. 
Name Mass 
Absolute R. T 
(Sec) 
Equation 
Correlation 
Coefficient 
Ethylbenzene 106 331.0 Y= +1.50237X – 0.324424 0.99783 
 
 
Figure 12: Calibration curve of ethylbenzene 
 
 
1 2 3 4 5 6 7
2.00
3.00
4.00
5.00
6.00
7.00
Concentration
R
a
t
i
o
3% STD:1
1% STD:1
2% STD:1
4% STD:1
5% STD:1
4% STD:3
5% STD:3
y= +1.50237x - 0.324424
r = 0.99783
54 
 
 
Styrene: 
 The calibration curve for styrene was constructed using the following 
concentrations: 2, 4, 6, 8 10%. Each standard was run in triplicate for  reproducibility of 
the results. The calibration curve for styrene is shown in figure 13 and the linearity is 
good with a correlation coefficient (R
2
= 0.99698). The internal standard used for styrene 
is ethylbenzene- d
8
 having a mass of 116 + 115 comes out at 324.64 sec. 
Name Mass 
Absolute R. T 
(Sec) 
Equation 
Correlation 
Coefficient 
Styrene 104 369.37 Y= + 2.761X - 1.12104 0.99787 
 
 
Figure 13: Calibration curve of styrene 
Cumene: 
 The calibration curve for cumene was constructed using the following 
concentrations: 1, 2, 3, 4, 5%. Each standard was run in triplicate for  reproducibility of 
2 4 6 8 10 12 14
5.00
7.50
10.0
12.5
15.0
17.5
20.0
22.5
25.0
27.5
Concentration
R
a
t
i
o
3% STD:1
1% STD:1
2% STD:1
4% STD:1
5% STD:1
5% STD:3
y= +2.761x - 1.12104
r = 0.99787
55 
 
 
the results. The calibration curve for cumene is shown in figure 14 and the linearity is 
good with a correlation coefficient (R
2
= 0.99753). The internal standard used for cumene 
is ethylbenzene- d
8
 having a mass of 116 + 115 comes out at 324.64 sec. 
Name Mass 
Absolute R. T 
(Sec) 
Equation 
Correlation 
Coefficient 
Cumene 120 407.84 Y= + 1.07585X - 0.316722 0.99753 
 
 
Figure 14: Calibration curve of cumene 
α- Methylstyrene: 
 The calibration curve for α- methylstyrene was constructed using following 
concentrations: 1, 2, 3, 4, 5%. Each standard was run in triplicate for  reproducibility of 
results. The calibration curve for α- methylstyrene is shown in figure 15 and the linearity 
is good with a correlation coefficient (R
2
= 0.99692). The internal standard used for α- 
Methylstyrene is ethylbenzene- d
8
 having a mass of 116 + 115 comes out at 324.64 sec. 
1 2 3 4 5 6 7
1.00
1.50
2.00
2.50
3.00
3.50
4.00
4.50
5.00
Concentration
R
a
t
i
o
3% STD:1
1% STD:1
2% STD:1
4% STD:1
5% STD:1
5% STD:3
y= +1.07585x - 0.316722
r = 0.99753
56 
 
 
Name Mass 
Absolute R. T 
(Sec) 
Equation 
Correlation 
Coefficient 
α- Methylstyrene 118 472.49 Y= + 1.46462x – 0.527142 0.99626 
 
 
Figure 15: Calibration curve of α- methylstyrene 
4.1.1.2 Limit of detection for aromatics in mass percent (1D) 
The limit of detection or the detection limit (LOD) is the lowest quantity of a 
compound that can be distinguished from the absence of that compound. The calculation 
method is again based on the slope and the intercept of the calibration curve. 
 
1 2 3 4 5 6 7
1.00
2.00
3.00
4.00
5.00
6.00
7.00
Concentration
R
a
t
i
o
3% STD:1
1% STD:1
2% STD:1
4% STD:1
5% STD:1
4% STD:3
5% STD:3
y= +1.46462x - 0.527142
r = 0.99626
57 
 
 
Table 11: Limit of detection for aromatics in mass percent 
Compound 1D (Mass Percent) 
Benzene 0.02 
Toluene 0.007 
Ethylbenzene 0.2 
Styrene 0.6 
Cumene 0.1 
α- Methylstyrene 0.2 
 
 Different grades of gasoline, diesel, polyflow and distillation standard D86 were 
qualitatively determined and then quantified using the calibration set 1. The retention 
time, area and mass percent of each the aromatic compounds in different grades of 
gasoline, diesel and distillation standard D86 are tabulated below. 
4.1.1.3 Distillation standard D 86 (1D) 
 The distillation standard D 86 was qualitatively determined and then quantified 
using the calibrated standards. Table 12 shows only the calibrated compounds, with their 
retention time, area and mass percent. D 86 contains only toluene and Cumene. 
Table 12: Quantified aromatics in D 86 in mass percent 
Compound Retention Time (sec) Area Mass Percent 
Benzene- d6 73.05 234196 7.2 
Toluene- d8 186.27 536014.6 7.2 
Toluene 194.11 4355544 32.8 
Ethylbenzene- d8 324.56 55481 7.2 
Cumene 408.21 783143.3 13.4 
Naphthalene- d8 656.28 91706 7.2 
58 
 
 
4.1.1.4 Gasoline samples (1D) 
 Different grades of gasoline like regular and super were collected from different 
places on different days. This gasoline sample was characterized and was quantified 
against standard calibration that contains six aromatic compounds. Each sample was run 
in triplicate to check the reproducibility of the method. All the gasoline samples were 
named according to their grade and the date they were collected and the format used in 
naming the samples is type, grade, the day it was collected (YY/ MM/ DD). All the 
aromatic compounds in the gasoline samples were listed below in mass percent. 
Gasoline super (130611): 
Gasoline super (130611) was qualitatively determined and then quantified using 
the calibrated standards. Table 13 shows only the calibrated compounds, with their 
retention time, area and mass percent. Gasoline super (130611) contains benzene, 
toluene, ethylbenzene and cumene which have 0.2, 12.0, 1.2 and 0.6 mass percent 
respectively of the six aromatic compounds. 
Table 13: Quantified aromatics in gasoline super (130611) in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72.91 561732.3 7.2 
Benzene 74.32 138877.3 0.2 
Toluene- d8 186.05 886809.7 7.2 
Toluene 192.95 3018553 12.1 
Ethylbenzene- d8 324.48 72569.33 7.2 
Ethylbenzene 330.72 108332 1.2 
Cumene 407.48 22399 0.6 
Naphthalene- d8 656.34 113648.3 7.2 
 
59 
 
 
Gasoline regular (130611): 
Gasoline regular (130611) was qualitatively determined and then quantified using 
the calibrated standards. Table 14 shows only the calibrated compounds, with their 
retention time, area and mass percent. Gasoline regular (130611) contains benzene, 
toluene, ethylbenzene and cumene which has 0.9, 6.5, 1.4 and 0.4 mass percent 
respectively of the six aromatic compounds 
Table 14: Quantified aromatics in gasoline regular (130611) in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72.89 538421.6 7.2 
Benzene 74.16 502686.3 0.9 
Toluene- d8 185.78 760428.3 7.2 
Toluene 192.15 1396424.6 6.5 
Ethylbenzene- d8 324.55 60151.3 7.2 
Ethylbenzene 330.64 104507 1.4 
Cumene 407.51 9290.7 0.4 
Naphthalene-d8 656.35 92289.3 7.2 
 
Gasoline regular (130522): 
Gasoline regular (130522) was qualitatively determined and then quantified using 
the calibrated standards. Table 15 shows only the calibrated compounds, with their 
retention time, area and mass percent. Gasoline regular (130522) contains benzene, 
toluene, ethylbenzene and cumene which has 0.4, 4.5, 1.0 and 0.42 mass percent 
respectively of the six aromatic compounds. 
60 
 
 
Table 15: Quantified aromatics in gasoline regular (130522) in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72.96 517231.7 7.2 
Benzene 74.31 216459 0.4 
Toluene- d8 185.67 686292 7.2 
Toluene 191.91 870442.3 4.5 
Ethylbenzene- d8 324.52 57583.33 7.2 
Ethylbenzene 330.83 65038 1.0 
Cumene 407.52 7604.63 0.4 
Naphthalene- d8 656.26 82324 7.2 
 
Gasoline regular (130505): 
Gasoline regular (130505) was qualitatively determined and then quantified using 
the calibrated standards. Table 16 shows only the calibrated compounds, with their 
retention time, area and mass percent. Gasoline super (130505) contains benzene, 
toluene, ethylbenzene and Cumene which has 0.3, 4.1, 1.2 and 0.4 mass percent 
respectively of the six aromatic compounds. 
 
 
 
 
 
61 
 
 
Table 16: Quantified aromatics in gasoline regular (130505) in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72.21 570382.66 7.2 
Benzene 73.56 207907.33 0.3 
Toluene- d8 185.15 859535 7.2 
Toluene 191.45 988876.33 4.1 
Ethylbenzene- d8 324.28 71690.67 7.2 
Ethylbenzene 330.5 104094.33 1.2 
Cumene 407.36 11371.1 0.4 
Naphthalene- d8 656.23 107566.67 7.2 
4.1.1.5 Diesel samples (1D) 
 Diesel samples were collected from different places on different days. These 
samples were characterized and were quantified against standard calibration that contains 
six aromatic compounds to check the reproducibility of the method. All the diesel 
samples were named according to their grade and the dates they were collected and the 
format of the date for the samples is yy/mm/dd. All the diesel samples were qualitatively 
determined and is then quantified using the calibration standard. All the diesel samples do 
not contain any aromatic content in them. Most of the diesel samples had decane 
derivatives in it when quantified. The complete peak table of diesel is shown in the table 
17. 
 
 
 
62 
 
 
Table 17: Peak table of diesel collected on different days 
Compound Retention Time(sec) Area Mass Percent 
Benzene - - - 
Toluene - - - 
Ethylbenzene - - - 
Styrene - - - 
Cumene - - - 
à-Methylstyrene - - - 
Benzene- d6 73.48 181157 7.2 
Toluene- d8 186.07 434284 7.2 
Ethylbenzene- d8 324.81 33099 7.2 
Naphthalene- d8 656.32 53138 7.2 
Unknown 1 587.44 26399 Not quantified 
Undecane 675.57 72942 Not quantified 
Tridecane 752.47 75592 Not quantified 
Hexadecane 801.52 16618 Not quantified 
Tridecane 838.9 69614 Not quantified 
Decane, 2,9-dimethyl 870.82 22817 Not quantified 
4.1.1.6 Polyflow samples 
The end product generated by the RES Polyflow process is a liquid known as 
pygas from which diesel fuel, octane enhancers and gasoline blend stocks can be 
produced. The pygas samples were collected from the reactor at different days and at 
different times and are named according to them. All the pygas samples were 
qualitatively determined and then quantified using the calibrated standards. All the 
quantified pygas samples, with their retention time, area and mass percent are shown in 
their respective tables.  
63 
 
 
130417 Post Scrub: 
Table 18: Quantified aromatics in 130417 post scrub in mass percent 
Compound Retention Time (sec) Area Mass Percent 
Benzene- d6 72.94 687776.5 7.2 
Benzene 74.16 791077.5 1.2 
Toluene- d8 185.87 1141726.5 7.2 
Toluene 192.38 2484210.5 7.7 
Ethylbenzene- d8 324.38 103799 7.2 
Ethylbenzene 330.57 334169.5 2.4 
Styrene 368.22 894330.5 3.6 
Cumene 407.54 5367.95 0.3 
à-Methylstyrene 471.96 17610.5 0.5 
Naphthalene-D8 656.19 131376 7.2 
 
130313 post scrub: 
Table 19: Quantified aromatics in 130313 post scrub in mass percent 
Compound Retention Time (sec) Area Mass Percent 
Benzene- d6 72.63 555038.7 7.2 
Benzene 73.82 1550722 2.9 
Toluene- d8 185.37 801934 7.2 
Toluene 191.66 923829 4.1 
Ethylbenzene- d8 324.26 66800 7.2 
Ethylbenzene 330.57 67365.3 0.9 
Styrene 367.96 172631 1.3 
Naphthalene- d8 656.12 91574.5 7.2 
 
 
64 
 
 
130313 pyrogas scrub: 
Table 20: Quantified aromatics in 130313 pyrogas scrub in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 73.19 588892.3 7.2 
Benzene 74.44 709632.7 1.2 
Toluene- d8 185.99 958630.7 7.2 
Toluene 192.15 766540.3 2.9 
Ethylbenzene- d8 324.42 88094.67 7.2 
Ethylbenzene 330.52 165896.7 1.5 
Styrene 368.05 368054.3 1.9 
Cumene 407.42 9060.7 0.4 
à-Methylstyrene 471.87 17829 0.5 
Naphthalene- d8 656.21 124778 7.2 
 
Hydro treated gasoline fraction: 
Table 21: Quantified aromatics in hydro treated gasoline fraction in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72.45 583422.3 7.2 
Benzene 73.73 383447 0.7 
Toluene- d8 185.46 973335.3 7.2 
Toluene 192.27 2418040 8.8 
Ethylbenzene- d8 324.45 87961.3 7.2 
Ethylbenzene 331.49 1395190 10.8 
Styrene 369.77 4020901 17.0 
Cumene 407.13 106681.3 1.4 
à-Methylstyrene 471.77 273235.7 2.5 
Naphthalene- d8 656.17 156481.3 7.2 
 
65 
 
 
111005 Dr- 1 heated 2x: 
Table 22: Quantified aromatics in 111005 Dr- 1 heated 2X in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 73.11 528779 7.2 
Benzene 74.41 366199.3 0.7 
Toluene- d8 185.86 866701 7.2 
Toluene 192.45 2362865 9.7 
Ethylbenzene- d8 324.54 75155 7.2 
Ethylbenzene 331.35 1332289 12.0 
Styrene 369.61 3901744 19.2 
Cumene 407.17 103168.3 1.6 
à-Methylstyrene 471.76 265254.7 2.8 
Naphthalene- d8 655.99 132827 7.2 
 
Set 2: 
Calibration and quantitation of aromatic compounds (1D): 
 A set of Calibration standards were freshly made on a different day and the 
qualitative, quantitative analysis of the gasoline, diesel and distillation standard D86 was 
determined to check the reproducibility of the results. The compound mass, retention 
time, equation of the line and the correlation coefficient of each of the calibrated 
compounds are shown in the table. Benzene- d6 was used as an internal standard for 
benzene, toluene- d8 was used as an internal standard for toluene and Ethylbenzene- d8 
was used as an internal standard for ethylbenzene, styrene, cumene and à-Methylstyrene. 
66 
 
 
Table 23: Equation of line and correlation coefficient of calibrated aromatics 
Compound Mass 
Retention 
Time(sec) 
Equation of Line 
Correlation 
Coefficient 
Benzene 78 73.62 Y= + 0.954137x - 0.0221691 0.99903 
Toluene 92 191.19 Y= + 0.291794x - 0.0425493 0.99885 
Ethylbenzene 106 330.25 Y= + 1.46861x - 1.15141 0.99749 
Styrene 104 368.29 Y= + 2.66367x - 1.15141 0.99581 
Cumene 120 407.13 Y= + 1.10755x - 0.381265 0.99708 
à-Methylstyrene 118 471.75 Y= + 1.43772x - 0.529426 0.99593 
 
 The limit of detection or the detection limit (LOD) is the lowest quantity of a 
compound that can be distinguished from the absence of that compound. The calculation 
method is again based on the slope and the intercept of the calibration curve. 
Table 24: Limit of detection for aromatics in mass percent 
Compound 1D (Mass Percent) 
Benzene 0.02 
Toluene 0.006 
Ethylbenzene 0.2 
Styrene 0.6 
Cumene 0.1 
Methyl styrene 0.2 
 
 All the samples were qualitatively determined and then quantified using their 
respective calibration curves. The retention time, quant mass, area and mass percent of 
the aromaticcompounds in different grades of gasoline, diesel and distillation standard 
D86 are tabulated below. 
67 
 
 
Distillation standard D 86: 
The distillation standard D 86 was qualitatively determined and then quantified 
using the calibrated standards. Table 25 shows only the calibrated compounds, with their 
retention time, area and mass percent. The quantified distillation standard D 86 contains 
only toluene and cumene in 32.3 and 13.2 mass % respectively of the six aromatic 
compounds. 
Table 25: Quantified aromatics in distillation standard D 86 in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 73.05 256717 7.2 
Toluene- d8 185.32 638363.3 7.4 
Toluene 193.09 5434350 32.3 
Ethylbenzene- d8 324.13 53025.67 7.4 
Cumene 407.66 751443.7 13.2 
Naphthalene- d8 655.93 84779.33 7.4 
 
Gasoline samples: 
 Different grades of gasoline like regular and super were collected from 
different places on different days. This gasoline sample was characterized and was 
quantified against standard calibration that contains six aromatic compounds to check the 
reproducibility of the method. All the gasoline samples were listed with their quantified 
aromatic content with their retention time, area and mass percent. 
 
 
68 
 
 
Gasoline super (130611): 
Table 26: Quantified aromatics in gasoline super (130611) in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72.05 690706 7.4 
Benzene 73.41 164162.7 0.3 
Toluene- d8 185.1 1123784 7.4 
Toluene 192.35 3526120 10.9 
Ethylbenzene- d8 323.85 99155.33 7.4 
Ethylbenzene 330.01 134816.7 1.1 
Cumene 406.99 29232 0.6 
Naphthalene- d8 655.97 158181 7.4 
 
Gasoline regular (130611): 
Table 27: Quantified aromatics in gasoline regular (130611) in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 71.96 715313.7 7.4 
Benzene 73.22 671810.7 1.0 
Toluene- d8 184.67 1142053 7.4 
Toluene 191.3 1883875 5.8 
Ethylbenzene- d8 323.78 99067.67 7.4 
Ethylbenzene 330.04 150518.7 1.3 
Cumene 407 12673.17 0.5 
Naphthalene-d8 656.05 151409.7 7.4 
 
 
 
69 
 
 
Gasoline regular (130522): 
Table 28: Quantified aromatics in gasoline regular (130522) in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72.43 609090.3 7.4 
Benzene 73.78 257123.3 0.5 
Toluene- d8 185.07 873386 7.4 
Toluene 191.32 1045274 4.2 
Ethylbenzene- d8 323.98 78162 7.4 
Ethylbenzene 330.26 82614 0.9 
Cumene 407.14 9765.23 0.5 
Naphthalene- d8 655.97 122436.3 7.4 
 
Gasoline Regular (130505): 
Table 29: Quantified aromatics in gasoline regular (130505)  in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72 687245.7 7.4 
Benzene 73.32 218200 0.4 
Toluene- d8 184.97 1093153 7.4 
Toluene 191.24 1081919 3.5 
Ethylbenzene- d8 323.87 94348.67 7.4 
Ethylbenzene 330.09 126295 1.1 
Cumene 406.91 17528 0.5 
Naphthalene- d8 656.18 171664.3 7.4 
 
 
 
70 
 
 
Diesel samples: 
 Diesel samples were collected from different places on different days. These 
samples were characterized and quantified against standard calibration that contains six 
aromatic compounds to check the reproducibility of the method. All the aromatic 
compounds in the gasoline samples were listed below in mass percent. Diesel samples 
collected on 130611, 130505 do not contain the six aromatic compounds present in the 
set of calibration standards. Most of the diesel samples had decane derivatives in it when 
quantified. The complete peak table of diesel is shown in the table 30. 
 
 
 
 
 
 
 
 
 
 
 
 
71 
 
 
Table 30: Peak table of diesel collected on different days in mass percent 
Compound Retention Time (sec) Area Mass Percent 
Benzene - - - 
Toluene - - - 
Ethylbenzene - - - 
Styrene - - - 
Cumene - - - 
à-Methylstyrene - - - 
Benzene-d6 73.25 256261 7.4 
Toluene-d8 185.53 586943 7.4 
Ethylbenzene- d8 324.19 43564 7.4 
Naphthalene-D8 656.08 84925 7.4 
Unknown 1 587.16 31207 Not Quantified 
Hexadecane 675.22 101224 Not Quantified 
Unknown 2 752.23 118185 Not Quantified 
Decane, 2,5,9-trimethyl- 801.41 60680 Not Quantified 
Hexadecane 838.8 51768 Not Quantified 
Hexadecane 870.63 22483 Not Quantified 
Decane, 6-ethyl-2-methyl- 899.25 45296 Not Quantified 
 
Polyflow samples: 
 The end product generated by the RES Polyflow process is pygas from which 
diesel fuel, octane enhancers and gasoline blend stocks are produced. The pygas samples 
were collected from the reactor at different days and at different times and are named 
according to them. All the quantified aromatic compounds in the pygas samples are listed 
below in mass percent with their retention time and area. 
 
72 
 
 
130417 post scrub: 
Table 31: Quantified aromatics in 130417 post scrub in mass percent 
Compound Retention Time (sec) Area Mass Percent 
Benzene- d6 72.05 773645.7 7.4 
Benzene 73.25 1004229 1.4 
Toluene- d8 185.1 1308338 7.4 
Toluene 192.23 3160319 8.4 
Ethylbenzene- d10 323.95 121685.3 7.4 
Ethylbenzene 330.26 430962.3 2.6 
Styrene 368.16 1190324 4.1 
Cumene 407.06 10553.7 0.4 
à-Methylstyrene 471.42 24889 0.5 
Naphthalene-D8 655.93 169313.7 7.4 
 
130313 post scrub: 
Table 32: Quantified aromatics in 130313 post scrub in mass percent 
Compound Retention Time (sec) Area Mass Percent 
Benzene- d6 72.53 605018.7 7.4 
Benzene 73.72 1720457 3.0 
Toluene- d8 184.99 879665.3 7.4 
Toluene 191.23 1049827 4.2 
Ethylbenzene- d10 323.93 76982.67 7.4 
Ethylbenzene 330.14 79336.67 0.9 
Styrene 367.64 210649 1.5 
Naphthalene- d8 655.95 101290.3 7.4 
 
 
73 
 
 
130313 pyrogas scrub: 
Table 33: Quantified aromatics in 130313 pyrogas Scrub in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72.19 597873.7 7.4 
Benzene 73.42 741893.3 1.3 
Toluene- d8 184.52 982413 7.4 
Toluene 190.89 796359.7 2.9 
Ethylbenzene- d10 323.9 92381.67 7.4 
Ethylbenzene 330.01 175429 1.5 
Styrene 367.64 394935.3 2.0 
Cumene 407 9358.767 0.4 
à-Methylstyrene 471.55 20542 0.5 
Naphthalene- d8 656.02 134896 7.4 
 
Hydro treated gasoline fraction: 
Table 34: Quantified aromatics in hydro treated gasoline fraction in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72.87 542846.3 7.4 
Benzene 74.15 356061.7 0.7 
Toluene- d8 185.26 903415.3 7.4 
Toluene 192.02 2234195 8.6 
Ethylbenzene- d10 324.27 83385.67 7.4 
Ethylbenzene 331.19 1252491 10.5 
Styrene 369.54 3687290 17.0 
Cumene 406.88 104627.3 1.5 
à-Methylstyrene 471.58 256728.7 2.5 
Naphthalene- d8 656.05 145533.7 7.4 
 
74 
 
 
111005 Dr- 1 heated 2X: 
Table 35: Quantified aromatics in 111005 Dr- 1 heated 2X in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72.27 447732.7 7.4 
Benzene 73.54 312112.7 0.7 
Toluene- d8 184.91 741600 7.4 
Toluene 191.5 1994131 9.3 
Ethylbenzene- d10 324.1 67861 7.4 
Ethylbenzene 331.04 1123544 11.5 
Styrene 369.47 3279778 18.6 
Cumene 406.94 93674 1.6 
à-Methylstyrene 471.59 225396 2.7 
Naphthalene- d8 655.91 124769.3 7.4 
 
4.1.2 Two dimensional gas chromatography 
 GC x GC, combined with the Pegasus high throughput TOFMS, has the potential 
to allow a significant reduction in chromatographic analysis time. The GC X GC thermal 
modulation system traps the higher volatility aliphatic and aromatics commonly found in 
all the volatile samples and a secondary column type with different conditions provides 
greater separation. The modulator placed between the columns, consists of a quad- jet 
system that creates two distinct trapping zones that traps and focuses all the effluent from 
the primary column before it is released into the secondary column. Qualitative and 
quantitative analysis of all the gasoline, diesel and Polyflow samples were conducted by 
GC x GC TOFMS. 
 
75 
 
 
Set 1: 
4.1.2.1 Calibration and quantitation of aromatic compounds (2D) 
 In order to quantitatively determine the fuel and hydrocarbon samples, calibration 
curve measurements were performed and the typical calibration curves for benzene, 
toluene, ethylbenzene, styrene, cumene, α- methyl styrene are shown in figures 16 to 21. 
In the calibration curves, X- axis represents retention time of the separation on the first 
dimension column and the y-axis represents the retention time on the secondary oven. 
Benzene: 
 The calibration curve for benzene was constructed using the following 
concentrations: 1, 2, 3, 4, 5 %. Each standard was run in triplicate for  reproducibility of 
the results. The calibration curve for benzene is shown in figure 16 and the linearity is 
good with a correlation coefficient (R
2
= 0.99990). The internal standard used for benzene 
is benzene- d6 having a mass of 84+83 comes out at 72, 2.920 secs. The first retention 
time is the separation on the first dimension column and the second retention time 
represents the retention time on the secondary oven. 
Name Mass 
Absolute R. T 
(Sec) 
Equation 
Correlation 
Coefficient 
Benzene 78 72, 2.970 Y= + 0.868726x + 0.140604 0.99990 
 
 
76 
 
 
 
Figure 16: Calibration curve of benzene 
Toluene 
 The calibration curve for toluene was constructed using the following 
concentrations: 1, 2, 3, 4, 5%. Each standard was run in triplicate for  reproducibility of 
the results. The calibration curve for toluene is shown in figure 8 and the linearity is good 
with a correlation coefficient (R
2
= 0.99993). The internal standard used for toluene is 
toluene- d
8
 having a mass of 100 + 99 comes out at 184, 5.290 secs. 
Name Mass 
Absolute R. T 
(Sec) 
Equation 
Correlation 
Coefficient 
Toluene 92 192, 5.150 Y= + 0.24661x + 0.0312776 0.99993 
 
 
1 2 3 4 5 6 7
1.00
1.50
2.00
2.50
3.00
3.50
4.00
Concentration
R
a
t
i
o
3% STD:6
1% STD:6
2% STD:6
4% STD:6
5% STD:6
y= +0.868726x + 0.140604
r = 0.99990
77 
 
 
 
Figure 17: Calibration curve of toluene 
 
Ethylbenzene: 
 The calibration curve for ethylbenzene was constructed using the following 
concentrations: 1, 2, 3, 4, 5%. Each standard was run in triplicate for  reproducibility of 
the results. The calibration curve for ethylbenzene is shown in figure 9 and the linearity is 
good with a correlation coefficient (R
2
= 0.99660). The internal standard used for 
ethylbenzene is ethylbenzene- d
8
 having a mass of 116 + 115 comes out at 328, 4.240 
secs. 
Name Mass Absolute R. T 
(Sec) 
Equation Correlation 
Coefficient 
Ethylbenzene 106 328, 4.430 Y= + 1.17374x + 0.108833 0.99660 
 
 
1 2 3 4 5 6 7
0.300
0.400
0.500
0.600
0.700
0.800
0.900
1.000
1.10
1.20
Concentration
R
a
t
i
o
3% STD:6
1% STD:6
2% STD:6
4% STD:6
5% STD:6
y= +0.24661x + 0.0312776
r = 0.99993
78 
 
 
 
Figure 18: Calibration curve of ethylbenzene 
Styrene: 
 The calibration curve for styrene was constructed using the following 
concentrations: 2, 4, 6, 8 10%. Each standard was run in triplicate for  reproducibility of 
the results. The calibration curve for styrene is shown in figure 10 and the linearity is 
good with a correlation coefficient (R
2
= 0.99925). The internal standard used for styrene 
is ethylbenzene- d
8
 having a mass of 116 + 115 comes out at 328, 4.240 secs. 
 
Name Mass 
Absolute R. T 
(Sec) 
Equation 
Correlation 
Coefficient 
Styrene 104 368, 4.8 Y= + 2.27666x - 0.0183661 0.99925 
 
 
1 2 3 4 5 6 7
1.50
2.00
2.50
3.00
3.50
4.00
4.50
5.00
5.50
Concentration
R
a
t
i
o
3% STD:6
1% STD:6
2% STD:6
4% STD:6
5% STD:6
3% STD:5
y= +1.17374x + 0.108833
r = 0.99660
79 
 
 
 
Figure 19: Calibration curve of styrene 
Cumene: 
 The calibration curve for cumene was constructed using the following 
concentrations: 1, 2, 3, 4, 5%. Each standard was run in triplicate for  reproducibility of 
the results. The calibration curve for cumene is shown in figure 11 and the linearity is 
good with a correlation coefficient (R
2
= 0.99913). The internal standard used for cumene 
is ethylbenzene- d
8
 having a mass of 116 + 115 comes out at 328, 4.240 secs. 
Name Mass 
Absolute R. T 
(Sec) 
Equation 
Correlation 
Coefficient 
Cumene 120 408, 4.07 Y= + 0.949077x - 0.0350854 0.99913 
 
 
2 4 6 8 10 12 14
6.00
8.00
10.0
12.0
14.0
16.0
18.0
20.0
22.0
Concentration
R
a
t
i
o
3% STD:6
1% STD:6
2% STD:6
4% STD:6
5% STD:6
y= +2.27666x - 0.0183661
r = 0.99925
80 
 
 
 
Figure 20: Calibration curve of cumene 
α- Methylstyrene: 
 The calibration curve for α- methylstyrene was constructed using the following 
concentrations: 1, 2, 3, 4, 5%. Each standard was run in triplicate for  reproducibility of 
the results. The calibration curve for α- methylstyrene is shown in figure 12 and the 
linearity is good with a correlation coefficient (R
2
= 0.99868). The internal standard used 
for cumene is ethylbenzene- d
8
 having a mass of 116 + 115 comes out at 328, 4.240 secs. 
Name Mass 
Absolute R. T 
(Sec) 
Equation 
Correlation 
Coefficient 
α- Methylstyrene 118 472, 4.540 Y= + 1.23089x - 0.106699 0.99868 
 
1 2 3 4 5 6 7
1.00
1.50
2.00
2.50
3.00
3.50
4.00
4.50
Concentration
R
a
t
i
o
3% STD:6
1% STD:6
2% STD:6
4% STD:6
5% STD:6
y= +0.949077x - 0.0350854
r = 0.99913
81 
 
 
 
Figure 21: Calibration curve of α- methyl styrene 
4.1.2.2 Limit of detection for aromatics in mass percent (2D) 
The limit of detection or the detection limit (LOD) is the lowest quantity of a 
compound that can be distinguished from the absence of that compound. The calculation 
method is again based on the slope and the intercept of the calibration curve. 
Table 36: Limit of detection for aromatics in mass percent 
Compound 2D (Mass Percent) 
Benzene 0.02 
Toluene 0.005 
Ethylbenzene 0.2 
Styrene 0.5 
Cumene 0.2 
Metstyrene 0.2 
 
1 2 3 4 5 6 7
2.00
3.00
4.00
5.00
6.00
Concentration
R
a
t
i
o
3% STD:6
1% STD:6
2% STD:6
4% STD:6
5% STD:6
y= +1.23089x - 0.106699
r = 0.99868
82 
 
 
 Different grades of gasoline, diesel, polyflow and distillation standard D86 were 
qualitatively determined and then quantified using the calibration set 1. The retention 
time, quant mass, area and mass percent of the aromatic compounds in different grades of 
gasoline, diesel and distillation standard D86 are tabulated below. 
4.1.2.3 Distillation standard D 86 
 The distillation standard D 86 was qualitatively determined and then quantified 
using the calibrated standards. Table 37 shows only the calibrated compounds, with their 
retention time (primary column followed by secondary column), area and mass percent. 
The quantified distillation standard D 86 contains only toluene and cumene in 28.98 and 
11.71 mass % respectively of the six aromatic compounds. 
Table 37: Quantified aromatics in distillation standard D 86 in mass percent 
Compound Retention Time (sec) Area Mass Percent 
Benzene- d6 72 , 2.920 778167 7.2 
Toluene- d8 184 , 5.290 1273751 7.2 
Toluene 192 , 5.370 9143276 29.0 
Ethylbenzene- d8 328 , 4.230 124116 7.2 
Cumene 408 , 4.130 1374799 11.7 
                Naphthalene-D8 
 
656 , 6.120 196841.7 7.2 
4.1.2.4 Gasoline samples 
 Different grades of gasoline like regular and super were collected from different 
places on different days. This gasoline sample was characterized and was quantified 
against standard calibration that contains six aromatic compounds to check the 
reproducibility of the method. All the aromatic compounds in the gasoline samples were 
83 
 
 
listed below in mass percent. The quantified gasoline samples with their retention time 
(primary column followed by secondary column), area and mass percent were listed in 
their respective tables. 
Gasoline super (130611): 
Table 38: Quantified aromatics in gasoline super (130611) in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72 , 2.970 1019042 7.2 
Benzene 72 , 3.020 282627.3 0.3 
Toluene- d8 184 , 5.280 1797112 7.2 
Toluene 192 , 5.210 5263786 11.8 
Ethylbenzne- d8 328 , 4.240 152410.7 7.2 
Ethylbenzene 328 , 4.420 233138 1.2 
Cumene 408 , 4.050 59225.33 0.5 
Naphthalene- d8 656 , 6.120 266794 7.2 
 
Gasoline regular (130611): 
Table 39: Quantified aromatics in gasoline regular (130611) in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72 , 2.990 964932.3 7.2 
Benzene 72 , 3.050 1037752 1.1 
Toluene- d8 184 , 5.280 1686046 7.2 
Toluene 192 , 5.160 2825337 6.7 
Ethylbenzne- d8 328 , 4.250 150868.7 7.2 
Ethylbenzene 328 , 4.430 240412.3 1.3 
Cumene 408 , 4.040 31926.33 0.4 
Naphthalene- d8 656 , 6.130 251053.7 7.2 
84 
 
 
Gasoline regular (130522): 
Table 40: Quantified aromatics in gasoline regular (130522) in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72 , 2.960 721356.7 7.2 
Benzene 72 , 3.020 388909.7 0.5 
Toluene- d8 184 , 5.250 1173270 7.2 
Toluene 192 , 5.110 1492085 4.4 
Ethylbenzne- d8 328 , 4.240 112321.7 7.2 
Ethylbenzene 328 , 4.420 131537 0.9 
Cumene 408 , 4.050 21890.33 0.3 
Naphthalene- d8 656 , 6.130 191031.7 7.2 
 
Gasoline regular (130505): 
Table 41: Quantified aromatics in gasoline regular (130505) in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72 , 2.970 732802.7 7.2 
Benzene 72 , 3.030 302162.7 0.3 
Toluene- d8 184 , 5.270 1230088 7.2 
Toluene 192 , 5.130 1376990 3.4 
Ethylbenzne- d8 328 , 4.230 109790.7 7.2 
Ethylbenzene 328 , 4.410 184347 1.0 
Cumene 408 , 4.040 26132 0.6 
Naphthalene- d8 656 , 6.120 191591.7 7.2 
 
85 
 
 
4.1.2.5 Diesel samples: 
 Diesel samples were collected from different places on different days. Diesel 
samples were characterized and were quantified against standard calibration that contains 
six aromatic compounds to check the reproducibility of the method. All the aromatic 
compounds in the diesel samples were listed below in mass percent. diesel samples 
collected on 130611, 130505 do not contain the six aromatic compounds present in the 
set of calibration standards. Most of the diesel samples had decane derivatives. 
Diesel Marathon (130611): 
Table 42: Quantified aromatics in diesel marathon (130611) in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72 , 2.950 108638 7.2 
Toluene- d8 184 , 5.190 194416 7.2 
Toluene 192 , 5.020 5232.4 0 
Ethylbenzne- d8 328 , 4.190 21214 7.2 
Naphthalene-D8 656 , 6.100 24048 7.2 
 
Diesel pilot (130611): 
Table 43: Quantified aromatics in diesel pilot (130611) in mass percent  
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72 , 2.940 346254 7.2 
Toluene- d8 184 , 5.240 493696 7.2 
Toluene 192 , 5.080 6849.833 0.0 
Ethylbenzne- d8 328 , 4.240 53721.33 7.2 
Ethylbenzene 328 , 4.430 1337.467 0.0 
Naphthalene- d8 656 , 6.140 88707.33 7.2 
86 
 
 
 
Diesel (130505): 
Table 44: Quantified aromatics in diesel (130505) in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72 , 2.960 423049.6667 7.2 
Toluene- d8 184 , 5.260 606754 7.2 
Toluene 192 , 5.100 10226.03333 0.0 
Ethylbenzne- d8 328 , 4.250 66510 7.2 
Ethylbenzene 328 , 4.460 1643.233333 0.0 
Naphthalene- d8 656 , 6.170 109770 7.2 
 
4.1.2.6 Polyflow samples: 
 The end product generated by the RES Polyflow process is pygas from which 
diesel fuel, octane enhancers and gasoline blend stocks are produced. The pygas samples 
were collected from the reactor at different days and at different times and are named 
according to them. The main purpose of this work is to characterize these different pygas 
samples and quantify them with the calibration standards by two dimensional gas 
chromatography using a thermal modulator. 
 
 
 
 
 
87 
 
 
130417 post scrub: 
Table 45: Quantified aromatics in 130417 post scrub in mass percent 
Compound Retention Time (sec) Area Mass Percent 
Benzene- d6 72 , 3.020 862955.7 7.2 
Benzene 72 , 3.080 999185.7 1.2 
Toluene- d8 184 , 5.290 1443342 7.2 
Toluene 192 , 5.190 3094072 8.6 
Ethylbenzne- d8 328 , 4.270 142831.3 7.2 
Ethylbenzene 328 , 4.460 365217 2.1 
Styrene 368 , 4.840 1171710 3.6 
Cumene 408 , 4.070 13047 0.4 
à-Methylstyrene 472 , 4.540 30942.67 0.5 
Naphthalene- d8 656 , 6.170 195703.7 7.2 
 
130313 Post scrub: 
Table 46: Quantified aromatics in 130313 post scrub in mass percent 
Compound Retention Time (sec) Area Mass Percent 
Benzene- d6 72 , 3.040 713056 7.2 
Benzene 72 , 3.100 2144589.3 3.3 
Toluene- d8 184 , 5.300 1173097 7.2 
Toluene 192 , 5.160 1358289 4.6 
Ethylbenzne- d8 328 , 4.270 118429.3 7.2 
Ethylbenzene 328 , 4.450 92896 1.0 
Styrene 368 , 4.810 290432.7 1.6 
Cumene 408 , 4.070 3984.2 0.3 
à-Methylstyrene 472 , 4.540 7118.0 0.4 
Naphthalene- d8 656 , 6.190 159615.6 7.2 
 
88 
 
 
130313 Pyrogas scrub: 
Table 47: Quantified aromatics in 130313 pyrogas scrub in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72 , 3.020 728225 7.2 
Benzene 72 , 3.070 937176 1.3 
Toluene- d8 184 , 5.300 1193479.3 7.2 
Toluene 192 , 5.160 996132 3.3 
Ethylbenzne- d8 328 , 4.270 129901.6 7.2 
Ethylbenzene 328 , 4.460 151300.3 1.6 
Styrene 368 , 4.820 496621.6 2.0 
Cumene 408 , 4.070 17623.3 0.5 
à-Methylstyrene 472 , 4.540 31517.6 0.6 
Naphthalene- d8 656 , 6.180 191103.6 7.2 
 
Hydro treated gasoline fraction: 
Table 48: Quantified aromatics in hydro treated gasoline fraction in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72 , 2.970 801458 7.2 
Benzene 72 , 3.030 509488.7 0.6 
Toluene- d8 184 , 5.310 1320768 7.2 
Toluene 192 , 5.210 3199752 9.7 
Ethylbenzne- d8 328 , 4.280 156968 7.2 
Ethylbenzene 328 , 4.470 526902.7 10.8 
Styrene 368 , 4.950 4549218 12.8 
Cumene 408 , 4.090 178861.3 1.2 
à-Methylstyrene 472 , 4.580 414013.7 2.2 
Naphthalene- d8 656 , 6.200 256383.7 7.2 
 
89 
 
 
111005 Dr- 1 Heated 2X: 
Table 49: Quantified aromatics in 111005 Dr- 1 heated 2X in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72 , 3.020 729611 7.2 
Benzene 72 , 3.070 535404.3 0.7 
Toluene- d8 184 , 5.310 1225945 7.2 
Toluene 192 , 5.220 3311649 10.8 
Ethylbenzne- d8 328 , 4.290 144501 7.2 
Ethylbenzene 328 , 4.480 590791 11.5 
Styrene 368 , 4.960 4779006 18.6 
Cumene 408 , 4.100 184475.3 1.4 
à-Methylstyrene 472 , 4.580 421419 2.5 
Naphthalene- d8 656 , 6.210 230253 7.2 
 
Set 2: 
Calibration and quantitation of aromatic compounds(2D): 
 Another set of calibration standards was freshly made on a different day and the 
qualitative, quantitative analysis of the gasoline, diesel and distillation standard D86 was 
determined to check the reproducibility of the results. The compound mass, retention 
time, equation of the line and the correlation coefficient of each of the calibrated 
compounds are shown in the table. Benzene- d6 was used as an internal standard for 
benzene, toluene- d8 was used as an internal standard for toluene and ethylbenzene d8 
was used as an internal standard for ethylbenzene, styrene, cumene and à-Methylstyrene. 
90 
 
 
Table 50: Equation of Line and Correlation Coefficient for aromatic compounds 
Compound Mass 
Retention 
Time(sec) 
Equation of Line 
Correlation 
Coefficient 
Benzene 78 72, 3.030 Y= + 0.967116x - 0.0333183 0.99966 
Toluene 92 192, 5.15 Y= + 0.280284x - 0.0195039 0.99970 
Ethylbenzene 106 328, 4.45 Y= + 1.94329x + 0.582849 0.99057 
Styrene 104 368, 4.86 Y= + 3.54404x + 1.04438 0.99295 
Cumene 120 408, 4.08 Y= + 1.47025x + 0.262839 0.99209 
à-Methylstyrene 118 472, 4.540 Y= + 1.96333x + 0.0729557 0.99447 
 
 The limit of detection or the detection limit (LOD) is the lowest quantity of a 
compound that can be distinguished from the absence of that compound. The calculation 
method is again based on the slope and the intercept of the calibration curve. 
Table 51: Limit of detection for aromatics in mass percent 
Compound Limit of Detection ( Mass Percent) 
Benzene 0.03 
Toluene 0.006 
Ethylbenzene 0.2 
Styrene 0.5 
Cumene 0.2 
Metstyrene 0.2 
 
 All the samples were qualitatively determined and then quantified using their 
respective calibration curves. The retention time, quant mass, area and mass percent of 
the aromaticcompounds in different grades of gasoline, diesel and distillation standard 
D86 are tabulated below. 
91 
 
 
Distillation standard D 86: 
 The quantified distillation standard D 86 contains only toluene and cumene in 
31.8 and 12.6 mass % respectively of the six aromatic compounds. 
Table 52: Quantified aromatics in distillation standard D 86 in mass percent 
Compound Retention Time (sec) Area Mass percent 
Benzene- d6 72 , 2.950 320209 7.4 
Toluene- d8 184 , 5.300 535097.3 7.4 
Toluene 192 , 5.270 4541254 31.8 
Ethylbenzene- d8 328 , 4.260 36677 7.4 
Cumene 408 , 4.130 578080.7 12.6 
              Naphthalene-D8 
 
656 , 6.180 67981.67 7.4 
 
Gasoline samples: 
 Different grades of gasoline like regular and super were collected from different 
places on different days. These gasoline samples were characterized and was quantified 
against standard calibration that contains six aromatic compounds to check the 
reproducibility of the method. All the aromatic compounds in the gasoline samples were 
listed below in mass percent. 
 
 
 
 
 
92 
 
 
Gasoline super (130611): 
Table 53: Quantified aromatics in gasoline super (130611) in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72 , 2.970 459747.7 7.4 
Benzene 72 , 3.020 112774.3 0.3 
Toluene- d8 184 , 5.320 781793.7 7.4 
Toluene 192 , 5.220 2348810 11.3 
Ethylbenzne- d8 328 , 4.270 52089.33 7.4 
Ethylbenzene 328 , 4.450 113881.7 1.5 
Cumene 408 , 4.090 22932.67 0.5 
Naphthalene- d8 656 , 6.190 108671.3 7.4 
 
Gasoline regular (130611): 
Table 54: Quantified aromatics in gasoline regular (130611) in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72 , 3.020 452644.3 7.4 
Benzene 72 , 3.080 450617.7 1.0 
Toluene- d8 184 , 5.310 755981 7.4 
Toluene 192 , 5.190 1198146 6.0 
Ethylbenzne- d8 328 , 4.280 57543.67 7.4 
Ethylbenzene 328 , 4.470 98849 1.3 
Cumene 408 , 4.090 10954.33 0.4 
Naphthalene- d8 656 , 6.210 95261 7.4 
 
 
 
93 
 
 
Gasoline regular (130522): 
Table 55: Quantified aromatics in gasoline regular (130522) in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72 , 3.010 435055.3 7.4 
Benzene 72 , 3.060 205395.3 0.5 
Toluene- d8 184 , 5.320 727211.7 7.4 
Toluene 192 , 5.190 850162 4.4 
Ethylbenzne- d8 328 , 4.300 60527.33 7.4 
Ethylbenzene 328 , 4.480 65365.67 1.0 
Cumene 408 , 4.110 9927.2 0.3 
Naphthalene- d8 656 , 6.230 100574.7 7.4 
 
Gasoline regular (130505): 
Table 56: Quantified aromatics in gasoline regular (130505) in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72 , 3.000 456770 7.4 
Benzene 72 , 3.060 146634 0.3 
Toluene- d8 184 , 5.320 759108.7 7.4 
Toluene 192 , 5.180 740321.7 3.7 
Ethylbenzne- d8 328 , 4.300 63669.33 7.4 
Ethylbenzene 328 , 4.480 70471.67 1.0 
Cumene 408 , 4.110 13124.67 0.4 
Naphthalene- d8 656 , 6.230 102470.3 7.4 
 
 
 
94 
 
 
Diesel samples: 
 Diesel samples were collected from different places on different days. These 
samples were characterized and was quantified against standard calibration that contains 
six aromatic compounds to check the reproducibility of the method. All the aromatic 
compounds in the diesel samples were listed below in mass percent. Diesel samples 
collected on 130611, 130505 do not contain the six aromatic compounds present in the 
set of calibration standards. The qualitative determination of the diesel samples had many 
decane derivatives in it. 
Diesel marathon (130611): 
Table 57: Quantified aromatics in diesel marathon (130611) in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72 , 2.990 279305 7.4 
Toluene- d8 184 , 5.300 415569.7 7.4 
Toluene 192 , 5.140 7919.433 0.1 
Ethylbenzne- d8 328 , 4.300 40990.67 7.4 
Ethylbenzene 328 , 4.480 1080.83 03 
Naphthalene-D8 656 , 6.260 62841.33 7.4 
 
 
 
 
 
 
95 
 
 
Diesel pilot (130611): 
Table 58: Quantified aromatics in diesel pilot (130611) in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72 , 3.000 99649.67 7.4 
Toluene- d8 184 , 5.310 148316.7 7.4 
Toluene 192 , 5.140 1782.267 0.1 
Ethylbenzne- d8 328 , 4.310 14305.67 7.4 
Ethylbenzene 328 , 4.500 372.5333 0.3 
Naphthalene- d8 656 , 6.280 22801.33 7.4 
 
Diesel (130505): 
Table 59: Quantified aromatics in diesel (130505) in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72 , 2.970 317896 7.4 
Toluene- d8 184 , 5.330 473785 7.4 
Toluene 192 , 5.140 6155.8 0.1 
Ethylbenzne- d8 328 , 4.310 45777 7.4 
Ethylbenzene 328 , 4.520 1045.18 0.3 
Naphthalene- d8 656 , 6.300 71670 7.4 
 
Polyflow samples: 
 The end product generated by the RES Polyflow process is pygas from which 
diesel fuel, octane enhancers and gasoline blend stocks are produced. The pygas samples 
were collected from the reactor at different days and at different times and are named 
according to them.  
96 
 
 
130417 Post scrub: 
Table 60: Quantified aromatics in 130417 post scrub in mass percent 
Compound Retention Time (sec) Area Mass Percent 
Benzene- d6 72 , 3.070 644083 7.4 
Benzene 72 , 3.120 853477.7 1.4 
Toluene- d8 184 , 5.370 1096559 7.4 
Toluene 192 , 5.270 2555852 8.8 
Ethylbenzne- d8 328 , 4.340 95402.67 7.4 
Ethylbenzene 328 , 4.530 319523.7 2.7 
Styrene 368 , 4.920 981317.7 4.6 
Cumene 408 , 4.140 9830.4 0.3 
à-Methylstyrene 472 , 4.630 24066.67 0.5 
Naphthalene- d8 656 , 6.360 108790 7.4 
 
130313 Post scrub: 
Table 61: Quantified aromatics in 130313 post scrub in mass percent 
Compound Retention Time (sec) Area Mass Percent 
Benzene- d6 72 , 3.090 511712.7 7.4 
Benzene 72 , 3.140 1655737 3.4 
Toluene- d8 184 , 5.360 866180 7.4 
Toluene 192 , 5.220 1001862 4.3 
Ethylbenzne- d8 328 , 4.340 72040 7.4 
Ethylbenzene 328 , 4.530 76379.33 1.0 
Styrene 368 , 4.900 217621.7          1.6 
Cumene 408 , 4.140 2748.4 0.2 
à-Methylstyrene 472 , 4.630 4520.3 0.3 
Naphthalene- d8 656 , 6.360 77445.6 7.4 
 
97 
 
 
130313 Pyrogas scrub: 
Table 62: Quantified aromatics in 130313 pyrogas scrub in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72 , 3.060 682718.7 7.4 
Benzene 72 , 3.110 862174 1.33 
Toluene- d8 184 , 5.370 1146006 7.4 
Toluene 192 , 5.220 899509 2.97 
Ethylbenzne- d8 328 , 4.350 62110.33 7.4 
Ethylbenzene 328 , 4.540 226514.3 1.91 
Styrene 368 , 4.910 484289 2.39 
Cumene 408 , 4.160 16829.33 0.36 
à-Methylstyrene 472 , 4.650 30904.33 0.49 
Naphthalene- d8 656 , 6.400 119236 7.4 
 
Hydro treated gasoline fraction: 
Table 63: Quantified aromatics in hydro treated gasoline fraction in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72 , 2.940 628202.3 7.4 
Benzene 72 , 2.990 436037.3 0.7 
Toluene- d8 184 , 5.320 1131187 7.4 
Toluene 192 , 5.220 2635501 8.8 
Ethylbenzne- d8 328 , 4.260 69066 7.4 
Ethylbenzene 328 , 4.510 1433116 10.9 
Styrene 368 , 4.940 4129093 17.8 
Cumene 408 , 4.090 148100.3 1.7 
à-Methylstyrene 472 , 4.570 342562 3.0 
Naphthalene- d8 656 , 6.180 197075.3 7.4 
 
98 
 
 
111005 Dr- 1 heated 2X: 
Table 64: Quantified aromatics in 111005 Dr- 1 heated 2X in mass percent 
Compound Retention Time(sec) Area Mass Percent 
Benzene- d6 72 , 2.940 542792.3 7.4 
Benzene 72 , 3.000 394880.7 0.8 
Toluene- d8 184 , 5.320 963692.3 7.4 
Toluene 192 , 5.210 2404326 9.4 
Ethylbenzne- d8 328 , 4.270 65472.67 7.4 
Ethylbenzene 328 , 4.500 1308891 11.7 
Styrene 368 , 4.920 3673365 18.5 
Cumene 408 , 4.080 131314.3 1.8 
à-Methylstyrene 472 , 4.560 290748.7 3.0 
Naphthalene- d8 656 , 6.180 157398.3 7.4 
 
 Following is a summary of the tabular data for quantified aromatic compounds in 
the distillation standard, gasoline, diesel fuel and pygas samples by two dimensional gas 
chromatoraphy. The concentrations are given in mass percent. 
 
 
 
 
 
 
 
99 
 
 
Set 1 (2D): 
Table 65: 2D data for samples in mass percent 
Compound  
Distillation 
standard 
Gasoline 
Super(130611) 
Regular 
(130611) 
Regular 
130522 
Regular 
130505 
Diesel Marathon 
(130611) 
Diesel Pilot 
(130611) 
Benzene 0 0.3 1.0 0.5 0.3 0 0 
Toluene 31.8 11.3 6.0 4.4 3.7 0 0 
Ethylbenzene 0 1.5 1.3 1 1.0 0 0 
Styrene 0 0 0 0 0 0 0 
Cumene 12.6 0.5 0.4 0.3 0.4 0 0 
α- methyl 
styrene 
0 0 0 0 0 0 0 
 
 
Diesel 
(130505) 
130417 Post 
Scrub 
130313 Post 
Scrub 
130313 Pyrogas 
Scrub 
Hydro Treated Gasoline 
Fraction 
111005 Dr- 1 
Heated 2X 
Benzene 0 1.4 3.4 1.3 0.7 0.8 
Toluene 0 8.8 4.4 3.0 8.7 9.4 
Ethylbenz
ene 
0 2.7 1.0 1.9 10.9 11.7 
Styrene 0 4.6 1.6 2.4 17.8 18.5 
Cumene 0 0.3 0.2 0.4 1.7 1.8 
α- methyl 
styrene 
0 0.4 0.3 0.5 3.0 3.0 
 
 
100 
 
 
Set 2 (2D): 
Table 66: 2D data for samples in mass percent 
Compound 
Distillation 
standard 
Gasoline 
Super(130611) 
Regular 
(130611) 
Regular 
130522 
Regular 
130505 
Diesel Marathon 
(130611) 
Diesel Pilot 
(130611) 
Benzene 0 0.3 1.1 0.4 0.3 0 0 
Toluene 29.0 11.8 6.7 4.4 3.4 0 0 
Ethylbenzene 1.6 1.2 1.3 0.9 1.0 0 0 
Styrene 0 0 0 0 0 0 0 
Cumene 11.7 0.5 0.4 0.3 0.6 0 0 
α- methyl 
styrene 
0 0 0 0 0 0 0 
 
Compound  
Diesel 
(130505) 
130417 Post 
Scrub 
130313 Post 
Scrub 
130313 Pyrogas 
Scrub 
Hydro Treated Gasoline 
Fraction 
111005 Dr- 1 
Heated 2X 
Benzene 0 1.2 3.3 1.3 0.6 0.6 
Toluene 0 8.6 4.6 3.3 9.7 10.8 
Ethylbenze
ne 
0 2.1 1.0 1.6 10.8 11.5 
Styrene 0 3.6 1.6 2.0 12.8 18.6 
Cumene 0 0.4 0.3 0.5 1.2 1.4 
α- methyl 
styrene 
0 0.5 0.4 0.6                 2.2 2.4 
 
101 
 
 
 Following is a summary of the tabular data for quantified aromatic compounds in 
the distillation standard, gasoline, diesel fuel and pugas samples by one dimensional gas 
chromatoraphy. The concentrations are given in mass percent. 
Table 67: 1D data for sample in mass percent 
Compound  
Distillation 
standard 
Gasoline 
Super(130611) 
Regular 
(130611) 
Regular 
130522 
Regular 
130505 
Diesel Marathon 
(130611) 
Diesel Pilot 
(130611) 
Benzene 0 0.2 1.0 0.4 0.3 0 0 
Toluene 32.8 12.0 6.5 4.5 4.1 0 0 
Ethylbenzene 0 1.2 1.4     1.0 1.2 0 0 
Styrene 0 0 0 0 0 0 0 
Cumene 13.4 0.6 0.4 0.4 0.4 0 0 
α- methyl 
styrene 
0 0 0 0 0 0 0 
 
 
 
 
 
 
 
 
102 
 
 
Compound 
Diesel 
(130505) 
130417 Post 
Scrub 
130313 Post 
Scrub 
130313 Pyrogas 
Scrub 
Hydro Treated Gasoline 
Fraction 
111005 Dr- 1 
Heated 2X 
Benzene 0 1.2 3.0 1.2 0.6 0.7 
Toluene 0 7.7 4.1 2.9 8.8 9.6 
Ethylbenzene 0 2.4 0.9           1.5 10.7 12.0 
Styrene 0 3.5 1.3          1.9 16.9 19.1 
Cumene 0 0.3 0 0.4 1.4 1.7 
α- methyl 
styrene 
0 0.5 0 0.5 2.5 2.8 
 
Table 68: 1D data for all samples in mass percent 
Compound 
Distillation 
standard 
Gasoline 
Super(130611) 
Regular 
(130611) 
Regular 
(130522) 
Regular 
(130505) 
Diesel Marathon 
(130611) 
Diesel Pilot 
(130611) 
Benzene 0 0.3 1.0 0.5 0.3 0 0 
Toluene 32.3 10.9 5.8 4.2 3.5 0 0 
Ethylbenzene 0 1.1 1.3 0.9 1.1 0 0 
Styrene 0 0 0 0 0 0 0 
Cumene 13.1 0.6 0.5 0.4 0.5 0 0 
α- methyl 
styrene 
0 0 0 0 0 0 0 
 
 
103 
 
 
 
Diesel 
(130505) 
130417 Post 
Scrub 
130313 Post 
Scrub 
130313 Pyrogas 
Scrub 
Hydro Treated Gasoline 
Fraction 
111005 Dr- 1 
Heated 2X 
Benzene 0 1.4 3.0 1.3 0.7 0.7 
Toluene 0 8.4 4.2 2.9 8.6 9.3 
Ethylbenzene 0 2.6 0.9 1.5 10.5 11.5 
Styrene 0 4.1 1.5 2.0 17.0 18.5 
Cumene 0 0.42 0 0.43 1.47 1.58 
Metstyrene 0 0.5 0 0.5 2.5 2.7 
 
4.1.3 Qualitative characterization and quantitation of gasoline, diesel fuel and pygas 
samples 
 The chromaTOF deconvolution software package processes the data and gives a 
complete sample assay which has peak table, hit table, mass spectra of each ion, a 3D 
image and total ion chromatogram of each sample. In other words, qualitative 
characterization of the sample and quantitative data for specific analyte of interest are 
provided by the software. 
Gasoline Super (130611): 
           The complete characterization of gasoline regular was shown with their peak table, 
total ion chromatogram, 3D image. Peak table shows all the compounds that are present 
in the Gasoline regular which is a qualitative determination. Each compound in the 
104 
 
 
sample was given with their type, retention time, quant mass, concentration, area and 
quantitation. 
Table 69: Peak table of gasoline super (130611) 
Name Type R.T. (s) 
Quant 
Masses 
Concentration Area 
Styrene/20130716 2d Not Found 104 - - 
à-Methylstyrene/20130716 2d Not Found 118 - - 
Benzene-D6 Quantified 72 , 2.910 84+83 7.2 1123589 
Benzene Quantified 72 , 2.960 78 0.16 312011 
Toluene-D8 Quantified 
184 , 
5.300 
100+99 7.2 1968065 
Toluene Quantified 
192 , 
5.230 
92 11.35 5571729 
1,4-Di(methyl-d3)benzene-d4 Quantified 
320 , 
4.480 
116+115 7.2 20973 
1,4-Di(methyl-d3)benzene-d4:2 Quantified 
328 , 
4.240 
116+115 7.2 161050 
Ethylbenzene Quantified 
328 , 
4.420 
106 1.23 249666 
Ethylbenzene:2 Quantified 
336 , 
4.290 
106 4.21 72249 
Benzene, (1-methylethyl)- Quantified 
408 , 
4.050 
120 0.44 61391 
Naphthalene-D8 Quantified 
656 , 
6.140 
136+135 7.2 275127 
Acetone Unknown 16 , 3.570 50 - 58945 
Butane, 1-chloro-2-methyl- Unknown 16 , 3.990 57 - 39502 
Butane, 2-methyl- Unknown 24 , 1.160 57 - 1450108 
Ethanol Unknown 24 , 1.390 45 - 3110400 
Butane, 2,2-dimethyl- Unknown 32 , 1.190 72 - 46848 
Pentane, 2-methyl- Unknown 32 , 1.250 55 - 463256 
105 
 
 
Name Type R.T. (s) 
Quant 
Masses 
Concentration Area 
Butane, 2,3-dimethyl- Unknown 40 , 1.330 71 - 775030 
1-Hexene, 4-methyl- Unknown 40 , 1.380 56 - 974144 
n-Hexane Unknown 48 , 1.430 57 - 523883 
2-Hexene, (Z)- Unknown 48 , 1.500 55 - 142235 
2-Pentene, 4-methyl- Unknown 48 , 1.560 69 - 79144 
Pentane, 2,4-dimethyl- Unknown 56 , 1.520 57 - 1717663 
Cyclopentane, methyl- Unknown 56 , 1.680 69 - 282686 
Unknown 1 Unknown 72 , 1.660 71 - 21069 
Cyclohexane Unknown 72 , 2.030 56 - 116130 
Pentane, 2,3-dimethyl- Unknown 80 , 1.800 56 - 2766959 
3-Hexene, 2-methyl-, (E)- Unknown 88 , 2.010 69 - 91921 
Pentane, 2,2,4-trimethyl- Unknown 96 , 1.840 57 - 
1509004
3 
Heptane, 3-methylene- Unknown 96 , 2.080 70 - 76313 
Heptane Unknown 
104 , 
2.030 
57 - 146036 
Unknown 2 Unknown 
104 , 
2.490 
81 - 20918 
3-Hexene, 3-methyl-, (E)- Unknown 
112 , 
2.340 
69 - 34475 
2-Butyn-1-ol Unknown 
120 , 
2.500 
69 - 29415 
Cyclohexane, methyl- Unknown 
120 , 
2.600 
55 - 155424 
Azetidine Unknown 
128 , 
2.140 
57 - 48514 
Hexane, 2,4-dimethyl- Unknown 
144 , 
2.300 
57 - 1890691 
Pentane, 2,3,4-trimethyl- Unknown 
160 , 
2.650 
71 - 1660565 
106 
 
 
Name Type R.T. (s) 
Quant 
Masses 
Concentration Area 
Heptane, 2,2,3,3,5,6,6-
heptamethyl- 
Unknown 
160 , 
2.810 
84 - 13909 
Pentane, 2,3,3-trimethyl- Unknown 
168 , 
2.700 
70 - 655643 
Hexane, 2,3-dimethyl- Unknown 
184 , 
2.610 
70 - 590264 
Unknown 3 Unknown 
184 , 
2.650 
69 - 25705 
Heptane, 2-methyl- Unknown 
192 , 
2.590 
57 - 172602 
Unknown 4 Unknown 
192 , 
2.660 
56 - 47773 
Toluene-D8 Unknown 
192 , 
4.910 
98 - 46493 
Heptane, 2-methyl- Unknown 
200 , 
2.450 
57 - 256993 
2(3H)-Furanone, dihydro-5-
methyl- 
Unknown 
200 , 
2.530 
56 - 170883 
Heptane, 3-methyl- Unknown 
208 , 
2.480 
57 - 261839 
Cyclohexane, 1,3-dimethyl-, cis- Unknown 
208 , 
2.820 
97 - 15379 
Hexane, 2,2,4-trimethyl- Unknown 
224 , 
2.310 
57 - 1146625 
Cyclopentane, 1-ethyl-3-methyl- Unknown 
232 , 
2.750 
55 - 67462 
Octane Unknown 
248 , 
2.450 
57 - 146230 
3-Ethyl-2-hexene Unknown 
256 , 
2.690 
83 - 12943 
Hexane, 2,3,5-trimethyl- Unknown 
272 , 
2.320 
85 - 56676 
Heptane, 2,2-dimethyl- Unknown 
280 , 
2.270 
57 - 45070 
Heptane, 2,6-dimethyl- Unknown 
296 , 
2.240 
57 - 61067 
Heptane, 2,5-dimethyl- Unknown 
304 , 
2.280 
57 - 216298 
4-Nonene, 3-methyl-, (Z)- Unknown 
312 , 
2.540 
55 - 25330 
Unknown 5 Unknown 
328 , 
2.360 
84 - 17362 
107 
 
 
Name Type R.T. (s) 
Quant 
Masses 
Concentration Area 
Heptane, 3,4-dimethyl- Unknown 
328 , 
2.390 
57 - 68318 
Decane, 5-methyl- Unknown 
336 , 
2.310 
57 - 34137 
Unknown 6 Unknown 
336 , 
4.330 
105 - 21940 
Octane, 2-methyl- Unknown 
344 , 
2.280 
71 - 68484 
o-Xylene Unknown 
344 , 
4.130 
91 - 2981637 
Pentane, 3-ethyl-3-methyl- Unknown 
352 , 
2.230 
85 - 22499 
Octane, 3-methyl- Unknown 
352 , 
2.290 
57 - 1053920 
Cyclopentane, 1-methyl-2-propyl- Unknown 
360 , 
2.620 
55 - 26925 
o-Xylene Unknown 
368 , 
4.400 
91 - 1254075 
Heptane, 3,3,5-trimethyl- Unknown 
376 , 
2.290 
71 - 133849 
Nonane Unknown 
384 , 
2.320 
57 - 115050 
Heptane, 2,3,6-trimethyl- Unknown 
400 , 
2.300 
57 - 227302 
2-Pyrrolidinone Unknown 
408 , 
2.230 
85 - 8785.7 
Decane, 2,5,9-trimethyl- Unknown 
416 , 
2.230 
57 - 68279 
Octane, 3,6-dimethyl- Unknown 
424 , 
2.270 
57 - 39934 
Heptane, 2,5-dimethyl- Unknown 
432 , 
2.280 
57 - 15846 
Benzene, propyl- Unknown 
440 , 
4.000 
91 - 350720 
2,2,7,7-Tetramethyloctane Unknown 
448 , 
2.280 
57 - 614952 
Benzene, 1-ethyl-2-methyl- Unknown 
448 , 
4.060 
105 - 1090053 
Benzene, 1,2,3-trimethyl- Unknown 
456 , 
3.930 
105 - 317954 
Heptane, 2,2,4,6,6-pentamethyl- Unknown 
464 , 
2.300 
57 - 481318 
108 
 
 
Name Type R.T. (s) 
Quant 
Masses 
Concentration Area 
Benzene, 1-ethyl-2-methyl- Unknown 
464 , 
4.320 
105 - 163376 
Nonane, 2,6-dimethyl- Unknown 
480 , 
2.390 
57 - 156930 
Benzene, 1,2,3-trimethyl- Unknown 
480 , 
4.130 
105 - 1271155 
Benzene, (2-methylpropyl)- Unknown 
496 , 
3.800 
91 - 36000 
Benzene acetaldehyde, à-methyl- Unknown 
496 , 
3.980 
105 - 28762 
o-Cymene Unknown 
512 , 
3.900 
119 - 53920 
Benzene, 1,2,3-trimethyl- Unknown 
512 , 
4.330 
105 - 259351 
Azetidine Unknown 
520 , 
2.230 
57 - 356060 
Pentane, 3,3-dimethyl- Unknown 
520 , 
2.390 
71 - 52894 
Benzene, 2-propenyl- Unknown 
520 , 
4.940 
117 - 67219 
Decane, 2,5,9-trimethyl- Unknown 
528 , 
2.320 
57 - 41876 
Benzene, 1,4-diethyl- Unknown 
536 , 
4.070 
105 - 36019 
Pentane, 3-ethyl-2,2-dimethyl- Unknown 
544 , 
2.400 
57 - 241953 
Benzene, 1-methyl-4-propyl- Unknown 
544 , 
3.860 
105 - 294176 
Benzene, butyl- Unknown 
544 , 
3.930 
91 - 122867 
Benzene, 1-methyl-3-(1-
methylethyl)- 
Unknown 
544 , 
4.030 
119 - 47554 
o-Cymene Unknown 
552 , 
3.860 
119 - 95006 
Benzene, 1-methyl-4-propyl- Unknown 
552 , 
4.130 
105 - 92846 
Methane, isocyanato- Unknown 
560 , 
2.350 
57 - 48435 
Hexane, 3,3,4,4-tetramethyl- Unknown 
560 , 
2.430 
71 - 26721 
Pentane, 2,2,3,4-tetramethyl- Unknown 
568 , 
2.360 
57 - 53158 
109 
 
 
Name Type R.T. (s) 
Quant 
Masses 
Concentration Area 
Benzene, 1-methyl-3-(1-
methylethyl)- 
Unknown 
568 , 
4.040 
119 - 196393 
Undecane, 4-methyl- Unknown 
576 , 
2.420 
57 - 22000 
Benzene, 1-methyl-3-(1-
methylethyl)- 
Unknown 
576 , 
4.050 
119 - 121426 
Benzene, 1-ethenyl-4-ethyl- Unknown 
576 , 
4.520 
117 - 9480.5 
Undecane, 4-methyl- Unknown 
584 , 
2.430 
57 - 30784 
Benzene, 1-methyl-4-butyl Unknown 
592 , 
3.780 
105 - 21592 
Benzene, (1,1-dimethylpropyl)- Unknown 
592 , 
3.840 
119 - 15738 
Benzene, 2-ethyl-1,4-dimethyl- Unknown 
592 , 
4.370 
119 - 30517 
o-Cymene Unknown 
600 , 
4.190 
117 - 12632 
Heptane, 4-ethyl-2,2,6,6-
tetramethyl- 
Unknown 
608 , 
2.320 
57 - 77778 
2,2,7,7-Tetramethyloctane Unknown 
616 , 
2.340 
57 - 14315 
Indan, 1-methyl- Unknown 
616 , 
4.830 
117 - 12978 
Hexadecane Unknown 
624 , 
2.380 
57 - 9680.4 
Benzene, (1,1-dimethylpropyl)- Unknown 
632 , 
3.820 
119 - 40433 
Benzenepropanal, á-methyl- Unknown 
632 , 
3.940 
105 - 28642 
Benzene, 1-methyl-3-(1-
methylethyl)- 
Unknown 
632 , 
4.500 
119 - 30861 
1H-Indene, 2,3-dihydro-4-methyl- Unknown 
632 , 
4.820 
117 - 33475 
Benzene, (1,1-dimethylpropyl)- Unknown 
640 , 
4.000 
119 - 37065 
Octane, 2,6-dimethyl- Unknown 
648 , 
2.330 
57 - 85000 
Benzene, (1-methylbutyl)- Unknown 
648 , 
4.010 
105 - 10578 
Benzene, 1-methyl-4-(1-
methylpropyl)- 
Unknown 
656 , 
4.030 
119 - 24921 
110 
 
 
Name Type R.T. (s) 
Quant 
Masses 
Concentration Area 
Azulene Unknown 
656 , 
6.250 
128 - 92586 
Benzene, 1,4-diethyl-2-methyl- Unknown 
672 , 
4.270 
133 - 19659 
Octane, 2,4,6-trimethyl- Unknown 
680 , 
2.430 
57 - 14205 
Decane, 2,2,7-trimethyl- Unknown 
696 , 
2.390 
57 - 29108 
Decane, 2,5,9-trimethyl- Unknown 
728 , 
2.280 
57 - 10016 
Naphthalene, 2-methyl- Unknown 
744 , 
4.740 
142 - 9397.5 
1H-Indene, 1-ethylidene- Unknown 
752 , 
4.330 
142 - 16363 
1H-Indene, 1-ethylidene- Unknown 
760 , 
4.440 
142 - 16091 
 
The hit table shows the possibility of all the compounds that are present with a 
given mass to charge ratio and at a particular retention time. Each compound was given 
with their similarity, type of library, ID of that compound, formula, molar mass and the 
contributor of the reference data. 
 
 
 
 
 
 
 
111 
 
 
Table 70: Hit table of benzene in gasoline regular (130611) 
Name Similarity Library Id Formula Weight Contributor 
Benzene 954 mainlib 43787 C6H6 78 
NIST Mass Spectrometry Data 
Center, 1990. 
Benzene 923 mainlib 43787 C6H6 78 
NIST Mass Spectrometry Data 
Center, 1990. 
Benzene 923 replib 10366 C6H6 78 Chemical Concepts 
Benzene 915 replib 10364 C6H6 78 
 
Benzene 906 replib 10367 C6H6 78 
Japan AIST/NIMC Database- 
Spectrum MS-NW- 75 
1,5-Hexadien-
3-yne 
897 mainlib 43770 C6H6 78 
 
1,5-Hexadiyne 892 replib 699 C6H6 78 
 
1,5-Hexadiyne 883 mainlib 1692 C6H6 78 
Japan AIST/NIMC Database- 
Spectrum MS-NW-4647 
2,4-Hexadiyne 860 mainlib 43743 C6H6 78 
 
2,4-Hexadiyne 853 replib 10356 C6H6 78 
NIST Mass Spectrometry Data 
Center, 1990. 
2,4-Hexadiyne 851 replib 10357 C6H6 78 Chemical Concepts 
 
The spectra compare the peak true spectra (compound spectra) with that of 
reference spectra before it assigns a particular chemical name to the compound. The 
spectrum of benzene is shown in the figure 22. 
 
112 
 
 
 
Figure 22: Spectra of benzene in gasoline regular (130611) 
The 3D image of the Gasoline super is shown in the figure 23. The x- axis represents the 
time on primary column and y- axis represents the retention time on secondary column. 
50 100 150 200 250 300 350 400 450 500
500
1000
 78 
 63 
Peak True - sample "SUPER GAS:1", peak 17, at 72 , 2.960 sec , sec
50 100 150 200 250 300 350 400 450 500
500
1000
 78 
 63 
Reference Spectrum - Calibration "20130716 2d ", Analyte "Benzene"
113 
 
 
 
Figure 23: 3D Image of gasoline super (130611) 
The total Ion chromatogram of the gasoline regular was shown in the figure 24. 
Each peak in the chromatogram represents a compound. The x- axis in the chromatogram 
represents the retention time and y- axis represents the intensity. 
 
 
Figure 24: Total ion chromatogram of gasoline super (130611) 
 
0
200
0
400
0
600
0
800
0
1000
100000
200000
300000
400000
500000
600000
700000
1st Time (s)
2nd T ime (s)
TIC
114 
 
 
Diesel pilot (130611): 
The complete characterization of diesel pilot is shown with their peak table, total 
ion chromatogram, 3D image. The peak table shows all the compounds that are present in 
the diesel pilot which is a qualitative determination. Each compound in the sample is 
given with their type, retention time, quant mass, concentration, area and quantitation.  
Table 71: Peak table of diesel pilot (130611) 
Name Type R.T. (s) 
Quant 
Masses 
Concentration Area 
Benzene/20130716 2d Not Found 78 - - 
1,4-Di(methyl-d3)benzene-
d4/20130716 2d 
Not Found 
116+11
5 
- - 
Styrene/20130716 2d Not Found 104 - - 
Benzene, (1-methylethyl)-/20130716 
2d 
Not Found 120 - - 
à-Methylstyrene/20130716 2d Not Found 118 - - 
Benzene-D6 Quantified 
72 , 
2.940 
84+83 7.2 296383 
Toluene-D8 Quantified 
184 , 
5.240 
100+99 7.2 410644 
Toluene Quantified 
192 , 
5.080 
92 -0.07 5881.9 
1,4-Di(methyl-d3)benzene-d4:2 Quantified 
328 , 
4.240 
116+11
5 
7.2 44817 
Ethylbenzene Quantified 
328 , 
4.430 
106 -0.06 1773.7 
Ethylbenzene:2 Quantified 
336 , 
4.200 
106 0.47 994.02 
Naphthalene-D8 Quantified 
656 , 
6.140 
136+13
5 
7.2 70503 
Toluene-D8 Unknown 
192 , 
4.900 
98 - 106039 
Cyclohexane, 1,3-dimethyl- Unknown 
208 , 
2.810 
55 - 16615 
Cyclohexane, ethyl- Unknown 
288 , 
2.930 
55 - 15445 
115 
 
 
Name Type R.T. (s) 
Quant 
Masses 
Concentration Area 
Octane, 2-methyl- Unknown 
344 , 
2.260 
57 - 14403 
o-Xylene Unknown 
344 , 
4.080 
91 - 28285 
Octane, 3-methyl- Unknown 
352 , 
2.290 
57 - 23755 
1-Ethyl-4-methylcyclohexane Unknown 
360 , 
2.690 
55 - 32660 
p-Xylene Unknown 
368 , 
4.360 
91 - 11534 
Nonane Unknown 
384 , 
2.320 
57 - 45601 
Cyclohexane, 1-ethyl-4-methyl-, cis- Unknown 
384 , 
2.800 
55 - 16078 
Cyclohexane, (1-methylethyl)- Unknown 
408 , 
2.840 
55 - 20676 
Pentane, 2,2,3,3-tetramethyl- Unknown 
416 , 
2.250 
57 - 27761 
Octane, 3,6-dimethyl- Unknown 
424 , 
2.260 
57 - 22886 
Octane, 2,3-dimethyl- Unknown 
432 , 
2.310 
57 - 12883 
Benzene, 1-ethyl-4-methyl- Unknown 
448 , 
4.060 
105 - 24014 
Hexane, 4-ethyl-2-methyl- Unknown 
456 , 
2.300 
57 - 73688 
Cyclohexane, 1-methyl-3-(1-
methylethyl)- 
Unknown 
456 , 
2.770 
55 - 18685 
Nonane, 3-methyl- Unknown 
464 , 
2.320 
57 - 28740 
Cyclohexane, 1-methyl-2-propyl- Unknown 
472 , 
2.650 
55 - 46066 
4-Decene, 4-methyl-, (E)- Unknown 
480 , 
2.800 
55 - 30906 
Benzene, 1,2,3-trimethyl- Unknown 
480 , 
4.120 
105 - 42606 
Decane Unknown 
496 , 
2.340 
57 - 162025 
Decane, 2,6,7-trimethyl- Unknown 
512 , 
2.330 
57 - 61185 
Cyclohexane, 1,4-dimethyl-2-
octadecyl- 
Unknown 
520 , 
2.620 
69 - 56188 
116 
 
 
Name Type R.T. (s) 
Quant 
Masses 
Concentration Area 
Cyclohexane, butyl- Unknown 
520 , 
2.840 
83 - 17477 
Nonane, 3,7-dimethyl- Unknown 
528 , 
2.370 
57 - 26534 
Cyclohexane, 2-ethyl-1,3-dimethyl- Unknown 
536 , 
2.660 
55 - 29613 
1,1'-Bicyclopentyl Unknown 
536 , 
3.420 
67 - 14794 
Benzene, 1-methyl-4-propyl- Unknown 
544 , 
3.870 
105 - 25558 
Benzene, butyl- Unknown 
544 , 
3.940 
91 - 10470 
Decane, 4-methyl- Unknown 
552 , 
2.360 
57 - 69580 
2,3,4-Trimethyl-hex-3-enal Unknown 
552 , 
2.760 
69 - 13302 
o-Cymene Unknown 
552 , 
3.880 
119 - 10844 
Decane, 3-methyl- Unknown 
560 , 
2.390 
57 - 44468 
Cyclohexane, 1-isopropyl-1-methyl- Unknown 
568 , 
2.750 
55 - 74720 
1,3,8-p-Menthatriene Unknown 
568 , 
4.050 
119 - 13624 
Cyclohexane, 1,4-dimethyl-2-
octadecyl- 
Unknown 
576 , 
2.740 
69 - 16291 
1,3,8-p-Menthatriene Unknown 
576 , 
4.070 
119 - 10538 
1-Nonylcycloheptane Unknown 
584 , 
2.810 
55 - 23458 
Undecane Unknown 
592 , 
2.410 
69 - 17613 
cis-Decalin, 2-syn-methyl- Unknown 
592 , 
3.230 
67 - 21107 
Decane Unknown 
608 , 
2.360 
57 - 47470 
1-Methyldecahydronaphthalene Unknown 
608 , 
3.340 
67 - 14321 
p-Cymene Unknown 
608 , 
4.170 
119 - 8641.6 
Undecane, 2,8-dimethyl- Unknown 
616 , 
2.400 
57 - 21284 
117 
 
 
Name Type R.T. (s) 
Quant 
Masses 
Concentration Area 
Cyclohexane, (1-methylethyl)- Unknown 
616 , 
2.910 
83 - 14246 
Cyclooctane, methyl- Unknown 
624 , 
2.760 
55 - 39679 
Indan, 1-methyl- Unknown 
632 , 
4.840 
117 - 9528.6 
Undecane, 4,6-dimethyl- Unknown 
640 , 
2.430 
57 - 133317 
Naphthalene, 1,2,3,4-tetrahydro- Unknown 
640 , 
5.220 
104 - 14292 
Naphthalene, decahydro-1,6-dimethyl- Unknown 
656 , 
3.190 
81 - 17917 
Cyclohexane, 1-methyl-4-(1-
methylbutyl)- 
Unknown 
664 , 
2.780 
55 - 31066 
Cyclohexane, 1-(cyclohexylmethyl)-3-
methyl-, cis- 
Unknown 
672 , 
2.900 
55 - 20410 
Dodecane Unknown 
680 , 
2.480 
55 - 61244 
Naphthalene, 1,2,3,4-tetrahydro-2-
methyl- 
Unknown 
688 , 
4.810 
104 - 10402 
Tridecane Unknown 
696 , 
2.460 
57 - 19115 
Octane, 2,7-dimethyl- Unknown 
704 , 
2.470 
57 - 14828 
(E)-Hex-3-enyl (E)-2-methylbut-2-
enoate 
Unknown 
704 , 
3.000 
83 - 12234 
Cyclopentane, (2-methylpropyl)- Unknown 
712 , 
2.840 
55 - 20561 
Undecane, 2,8-dimethyl- Unknown 
728 , 
2.320 
57 - 73505 
Cyclopentane, 2-isopropyl-1,3-
dimethyl- 
Unknown 
728 , 
2.600 
69 - 45349 
Naphthalene, 1,2,3,4-tetrahydro-5-
methyl- 
Unknown 
728 , 
4.510 
118 - 9858.8 
Dodecane, 4,6-dimethyl- Unknown 
736 , 
2.210 
57 - 71841 
Tridecane Unknown 
752 , 
2.170 
57 - 77509 
Cyclooctane, 1,4-dimethyl-, cis- Unknown 
752 , 
2.350 
83 - 26658 
Tridecane Unknown 
760 , 
2.060 
57 - 144685 
118 
 
 
Name Type R.T. (s) 
Quant 
Masses 
Concentration Area 
Naphthalene, 1,2,3,4-tetrahydro-1,1-
dimethyl- 
Unknown 
768 , 
3.520 
145 - 23536 
Cyclopentane, 1-butyl-2-propyl- Unknown 
776 , 
2.260 
69 - 21688 
Cyclohexane, 2-propenyl- Unknown 
776 , 
2.320 
55 - 44502 
Dodecane, 2,7,10-trimethyl- Unknown 
792 , 
1.960 
57 - 111144 
Cyclopentane, 1-methyl-3-(2-
methylpropyl)- 
Unknown 
800 , 
2.150 
55 - 241198 
Naphthalene, 1,2,3,4-tetrahydro-5,7-
dimethyl- 
Unknown 
800 , 
3.390 
145 - 10970 
Tetradecane Unknown 
808 , 
1.930 
57 - 192030 
Undecane, 2,8-dimethyl- Unknown 
832 , 
1.880 
57 - 108749 
Hexadecane Unknown 
840 , 
1.940 
57 - 146991 
Cyclopentane, 1-pentyl-2-propyl- Unknown 
840 , 
2.060 
83 - 41988 
Cyclohexane, 1-methyl-3-propyl- Unknown 
848 , 
2.080 
55 - 82330 
Hexadecane Unknown 
864 , 
1.880 
57 - 73146 
Cyclohexane, 1,1'-(1,2-dimethyl-1,2-
ethanediyl)bis- 
Unknown 
864 , 
2.050 
69 - 38317 
Hexadecane Unknown 
872 , 
1.930 
57 - 112472 
Cyclooctane, 1,4-dimethyl-, cis- Unknown 
872 , 
1.940 
55 - 51249 
Undecane Unknown 
888 , 
1.890 
57 - 73067 
2,2-Dimethyl-3-heptene trans Unknown 
888 , 
2.050 
69 - 34368 
Cyclohexane, 1-ethyl-1,3-dimethyl-, 
trans- 
Unknown 
896 , 
2.060 
55 - 26836 
Hexadecane Unknown 
904 , 
1.910 
57 - 94114 
Cyclohexane, 1,4-dimethyl-2-
octadecyl- 
Unknown 
904 , 
1.920 
69 - 21755 
Cyclohexane, 1-methyl-4-(1-
methylbutyl)- 
Unknown 
912 , 
2.050 
55 - 23540 
119 
 
 
Name Type R.T. (s) 
Quant 
Masses 
Concentration Area 
Hexadecane Unknown 
920 , 
1.910 
57 - 43234 
Cyclohexane, 1,1'-(1,2-dimethyl-1,2-
ethanediyl)bis-, (R*,R*)-(ñ)- 
Unknown 
920 , 
2.100 
55 - 25635 
Dodecane, 2-methyl- Unknown 
928 , 
1.950 
57 - 71307 
2-Octene, 4-ethyl-, (E)- Unknown 
928 , 
1.960 
55 - 28670 
Borane, [1,2-bis(1-
methylethyl)butyl]bis(1-methylethyl)- 
Unknown 
936 , 
2.070 
55 - 64557 
Hexadecane Unknown 
944 , 
1.930 
57 - 17410 
Octane, 2,7-dimethyl- Unknown 
952 , 
1.980 
57 - 49983 
Decane, 2,5,9-trimethyl- Unknown 
968 , 
1.950 
57 - 12453 
Hexadecane Unknown 
976 , 
2.000 
57 - 41443 
Sulfurous acid, 2-ethylhexyl isohexyl 
ester 
Unknown 
1000 , 
2.010 
57 - 19049 
120 
 
 
 
 
 
Figure 25: 3D Image of diesel pilot (130611) 
 
 
Figure 26: Total ion chromatogram of diesel pilot (130611) 
Distillation standard D 86: 
The complete characterization of Distillation Standard D 86 is shown with their 
peak table, total ion chromatogram, and 3D image. The peak table shows all the 
0
200
0
400
0
600
0
800
0
1000
60000
70000
80000
90000
100000
110000
120000
130000
140000
150000
1st Time (s)
2nd T ime (s)
TIC
121 
 
 
compounds that are present in the Distillation Standard D 86 which is a qualitative 
determination. Each compound in the sample is given with their type, retention time, 
quant mass, concentration, area and quantitation. 
Table 72: Peak table of distillation standard D 86 
Name Type R.T. (s) Quant Masses Concentration Area 
Benzene/20130716 2d Not Found 78 
  
Ethylbenzene/20130716 2d Not Found 106 
  
Styrene/20130716 2d Not Found 104 
  
à-Methylstyrene/20130716 2d Not Found 118 
  
Benzene-D6 Quantified 72 , 2.920 84+83 7.2 804034 
Toluene-D8 Quantified 184 , 5.280 100+99 7.2 1307310 
Toluene Quantified 192 , 5.360 92 28.86 9344674 
1,4-Di(methyl-d3)benzene-d4 Quantified 320 , 4.490 116+115 7.2 10724 
1,4-Di(methyl-d3)benzene-d4:2 Quantified 328 , 4.230 116+115 7.2 129697 
Ethylbenzene:2 Quantified 336 , 4.340 106 1.39 16491 
Benzene, (1-methylethyl)- Quantified 408 , 4.140 120 11.56 1418051 
Naphthalene-D8 Quantified 656 , 6.110 136+135 7.2 205554 
Dimethyl ether Unknown 24 , 1.320 45 
 
22633 
Pentane Unknown 24 , 1.590 55 
 
170367 
Pentane Unknown 32 , 1.200 49 
 
2698.4 
n-Hexane Unknown 48 , 1.450 57 
 
1929120 
Cyclobutane, ethyl- Unknown 56 , 1.690 56 
 
11941 
122 
 
 
Name Type R.T. (s) Quant Masses Concentration Area 
Cyclohexane Unknown 72 , 2.110 56 
 
7505338 
Methane, isocyanato- Unknown 96 , 1.790 57 
 
228750 
Heptane Unknown 104 , 2.110 71 
 
2674657 
Toluene-D8 Unknown 192 , 4.930 98 
 
215397 
Toluene Unknown 200 , 4.830 91 
 
1348690 
o-Xylene Unknown 344 , 4.160 91 
 
4459654 
o-Xylene Unknown 368 , 4.420 91 
 
2409482 
Naphthalene, decahydro-, trans- Unknown 536 , 3.470 67 
 
1655249 
Spiro[4.5]decane Unknown 576 , 3.800 67 
 
1207418 
Spiro[4.5]decane Unknown 584 , 3.620 67 
 
63764 
 
123 
 
 
 
Figure 27: 3D Image of distillation standard D 86 
 
 
Figure 28: Total ion chromatogram of distillation standard D 86 
130417 Post scrub: 
The complete characterization of 130417 Post Scrub was shown with their peak 
table, total ion chromatogram, and 3D image. The peak table shows all the compounds 
that are present in the 130417 Post Scrub which is a qualitative determination. Each 
0
200
0
400
0
600
0
800
0
1000
200000
400000
600000
800000
1e+006
1st Time (s)
2nd T ime (s)
TIC
124 
 
 
compound in the sample is given with their type, retention time, quant mass, 
concentration, area and quantitation.  
Table 73: Peak table of 130417 post scrub 
Name Type R.T. (s) 
Quant 
Masses 
Concentration Area 
Benzene-D6 Quantified 72 , 3.020 84+83 7.2 965237 
Benzene Quantified 72 , 3.080 78 1.12 1070912 
Toluene-D8 Quantified 184 , 5.290 100+99 7.2 1631630 
Toluene Quantified 192 , 5.190 92 8.52 3478796 
1,4-Di(methyl-d3)benzene-d4 Quantified 320 , 4.500 116+115 7.2 15304 
1,4-Di(methyl-d3)benzene-d4:2 Quantified 328 , 4.270 116+115 7.2 161991 
Ethylbenzene Quantified 328 , 4.460 106 2.03 404487 
Ethylbenzene:2 Quantified 336 , 4.230 106 5.69 99946 
Styrene Quantified 368 , 4.840 104 3.64 1340127 
Benzene, (1-methylethyl)- Quantified 408 , 4.070 120 0.14 15305 
à-Methylstyrene Quantified 472 , 4.540 118 0.27 35666 
Naphthalene-D8 Quantified 656 , 6.170 136+135 7.2 224483 
1-Propene, 2-methyl- Unknown 16 , 2.560 50 
 
132438 
Cyclopropane, ethyl- Unknown 24 , 1.240 55 
 
2283846 
Unknown 1 Unknown 24 , 1.360 45 
 
11220 
2-Pentene, (E)- Unknown 32 , 1.280 54 
 
60981 
1,4-Pentadiene Unknown 32 , 1.390 68 
 
197084 
Unknown 2 Unknown 32 , 1.510 66 
 
55632 
125 
 
 
Name Type R.T. (s) 
Quant 
Masses 
Concentration Area 
Pentane, 2-methyl- Unknown 40 , 1.360 71 
 
295565 
Cyclopentane, bromo- Unknown 40 , 1.490 67 
 
244419 
1-Pentene, 2-methyl- Unknown 40 , 1.540 84 
 
590842 
1H-Tetrazole, 5-methyl- Unknown 48 , 1.530 56 
 
2957711 
2-Pentene, 3-methyl-, (E)- Unknown 48 , 1.620 69 
 
1368003 
Cyclopentene, 3-methyl- Unknown 48 , 1.760 82 
 
55119 
5H-Tetrazol-5-amine Unknown 56 , 1.670 57 
 
59902 
2-Hexene, (E)- Unknown 56 , 1.690 55 
 
316788 
Cyclopentane, methyl- Unknown 56 , 1.740 56 
 
612828 
Cyclopropane, (1-
methylethylidene)- 
Unknown 56 , 1.840 67 
 
169268 
1-Pentene, 2,4-dimethyl- Unknown 64 , 1.800 56 
 
606363 
1,3-Pentadiene, 2-methyl-, (E)- Unknown 64 , 2.030 67 
 
398328 
1,3-Cyclopentadiene, 1-methyl- Unknown 64 , 2.260 80 
 
73238 
Methyl propargyl ether Unknown 72 , 1.840 70 
 
41793 
6-Oxabicyclo[3.1.0]hexane Unknown 72 , 1.890 55 
 
383598 
Ethanone, 1-(1-methyl-2-
cyclopenten-1-yl)- 
Unknown 72 , 2.040 81 
 
456879 
(Z),(Z)-2,4-Hexadiene Unknown 72 , 2.110 67 
 
1113021 
1H-Tetrazol-5-amine Unknown 80 , 1.810 85 
 
27678 
1-Hexene, 5-methyl- Unknown 80 , 1.920 56 
 
171581 
2,3-Dimethyl-1,4-pentadiene Unknown 80 , 2.050 81 
 
40689 
Cyclopropane, (1-
methylethylidene)- 
Unknown 80 , 2.420 67 
 
73766 
126 
 
 
Name Type R.T. (s) 
Quant 
Masses 
Concentration Area 
3-Hexen-1-yne Unknown 80 , 2.730 79 
 
80277 
Butanoic acid, 1,1-
dimethylethyl ester 
Unknown 88 , 1.910 57 
 
29539 
Cyclopentane, 1,3-dimethyl-, 
cis- 
Unknown 88 , 2.110 70 
 
88195 
Aminoacetonitrile Unknown 88 , 2.160 55 
 
124549 
Pyridine, 2-chloro-6-(2-
furanylmethoxy)-4-
(trichloromethyl)  
Unknown 88 , 2.300 81 
 
37023 
Cyclohexene Unknown 88 , 2.590 67 
 
278301 
1-Heptene Unknown 96 , 2.250 56 
 
2224603 
Borane, ethylisopropylmethyl- Unknown 96 , 2.400 81 
 
302744 
Heptane Unknown 104 , 2.140 57 
 
913157 
1,4-Hexadiene, 4-methyl- Unknown 104 , 2.600 81 
 
286056 
(Z)-3-Heptene Unknown 112 , 2.450 56 
 
241356 
1,3-Pentadiene, 2,3-dimethyl- Unknown 112 , 2.780 81 
 
236117 
1-Heptene Unknown 120 , 2.700 55 
 
534632 
1,5-Pentanediol, O,O'-di(3-
methylbut-2-enoyl)- 
Unknown 120 , 2.780 82 
 
46745 
3-Heptyne Unknown 120 , 2.950 81 
 
166155 
Vinylcyclopentane Unknown 128 , 3.010 67 
 
91348 
Methyl methacrylate Unknown 128 , 4.470 69 
 
117985 
Cyclopentane, ethyl- Unknown 136 , 2.870 69 
 
85994 
1,1'-Bicyclopropyl Unknown 136 , 3.090 54 
 
26520 
Butane, 2-cyclopropyl- Unknown 144 , 2.660 55 
 
36034 
Cyclohexene, 4-methyl- Unknown 144 , 3.420 81 
 
129853 
127 
 
 
Name Type R.T. (s) 
Quant 
Masses 
Concentration Area 
Bicyclo[4.1.0]heptane Unknown 152 , 3.600 81 
 
40353 
1-Methylcyclohexa-2,4-diene Unknown 152 , 3.900 79 
 
36990 
Isopropylcyclobutane Unknown 160 , 2.800 55 
 
27338 
1-Methylcyclohexa-2,4-diene Unknown 160 , 4.090 79 
 
26807 
2-Octene, (Z)- Unknown 168 , 2.920 56 
 
53720 
2,3-Dimethyl-1,4-pentadiene Unknown 168 , 3.700 81 
 
62346 
1,3,5-Hexatriene, 3-methyl-, 
(E)- 
Unknown 168 , 4.270 77 
 
18486 
Cyclohexene, 4-bromo- Unknown 176 , 3.590 81 
 
94717 
1-Ethylcyclopentene Unknown 176 , 3.650 67 
 
271623 
1-Hexene, 3,3-dimethyl- Unknown 184 , 2.850 69 
 
164418 
1-Methylcyclohexa-1,3-diene Unknown 184 , 4.410 79 
 
21119 
Heptane, 2,5-dimethyl- Unknown 192 , 2.580 57 
 
54241 
Cyclohexene, 3-methyl- Unknown 192 , 3.830 81 
 
190793 
Toluene-D8 Unknown 192 , 4.910 98 
 
91723 
Heptane, 4-methyl- Unknown 200 , 2.490 70 
 
431065 
3-Heptyne Unknown 200 , 3.590 81 
 
111053 
Toluene Unknown 200 , 4.810 91 
 
21205 
Unknown 3 Unknown 208 , 2.480 57 
 
37091 
Unknown 4 Unknown 208 , 2.820 55 
 
60585 
Spiropentane, propyl- Unknown 216 , 3.060 67 
 
17747 
1,3-Pentadiene, 2,3-dimethyl- Unknown 216 , 3.600 81 
 
25348 
128 
 
 
Name Type R.T. (s) 
Quant 
Masses 
Concentration Area 
1-Methylcyclohexa-2,4-diene Unknown 216 , 4.060 79 
 
22948 
Cyclooctene, (Z)- Unknown 224 , 3.060 67 
 
21686 
Cyclobutane, 1,2,3,4-
tetramethyl- 
Unknown 232 , 2.740 56 
 
204536 
1-Octene Unknown 240 , 2.700 55 
 
749880 
Cyclopentene, 1,2,3-trimethyl- Unknown 240 , 3.140 95 
 
29148 
Cyclopentanone Unknown 240 , 6.970 55 
 
35561 
Octane Unknown 248 , 2.480 57 
 
288176 
5,5-Dimethyl-1,3-hexadiene Unknown 248 , 2.930 95 
 
35881 
3-Octene, (Z)- Unknown 256 , 2.670 69 
 
101379 
2-Octene, (Z)- Unknown 264 , 2.690 55 
 
63359 
Bicyclo[2.1.0]pentane, 1,4-
dimethyl- 
Unknown 264 , 2.970 81 
 
37306 
Cyclopentene, 1,2,3-trimethyl- Unknown 264 , 3.020 95 
 
18547 
1-Hexene, 3,3,5-trimethyl- Unknown 272 , 2.490 69 
 
23936 
1-Heptene, 3-methyl- Unknown 272 , 2.740 56 
 
19310 
1-Propylcyclopentene Unknown 272 , 3.110 67 
 
35521 
Hexane, 2,3,4-trimethyl- Unknown 280 , 2.330 57 
 
29678 
Unknown 5 Unknown 280 , 3.140 55 
 
30204 
Cyclohexene, 1,6-dimethyl- Unknown 280 , 3.180 67 
 
81626 
Cyclohexane, 1,3,5-trimethyl-, 
(1à,3à,5à)- 
Unknown 288 , 2.580 69 
 
120666 
Cyclohexane, ethyl- Unknown 288 , 2.940 83 
 
36707 
4-Decyne Unknown 288 , 3.000 67 
 
28892 
129 
 
 
Name Type R.T. (s) 
Quant 
Masses 
Concentration Area 
2,3-Dimethyl-2-heptene Unknown 304 , 2.520 55 
 
134904 
1-Ethyl-5-methylcyclopentene Unknown 304 , 3.040 81 
 
19260 
2,4-Dimethyl-1-heptene Unknown 312 , 2.560 55 
 
711356 
Cyclopentene, 3-propyl- Unknown 312 , 3.160 67 
 
28151 
4-Ethylcyclohexene Unknown 312 , 3.340 81 
 
14089 
Cyclohexane, 1,3,5-trimethyl- Unknown 320 , 2.670 69 
 
125971 
Cyclopropane, 1,2-dimethyl-3-
pentyl- 
Unknown 328 , 2.560 55 
 
14220 
Cyclohexene, 3,3,5-trimethyl- Unknown 344 , 2.860 109 
 
11005 
Cyclohexene, 3-ethyl- Unknown 344 , 3.250 81 
 
33401 
o-Xylene Unknown 344 , 4.100 91 
 
47835 
Octane, 3-methyl- Unknown 352 , 2.300 57 
 
15200 
2(5H)-Furanone, 5-(2-methyl-2-
propenyl)- 
Unknown 352 , 2.860 55 
 
15914 
Cyclohexene, 3,3,5-trimethyl- Unknown 352 , 2.920 67 
 
31531 
Cycloheptane, methyl- Unknown 360 , 2.610 55 
 
16469 
Unknown 6 Unknown 368 , 2.560 56 
 
15398 
Unknown 7 Unknown 368 , 2.630 55 
 
26264 
p-Xylene Unknown 368 , 4.430 91 
 
16785 
1-Nonene Unknown 376 , 2.520 56 
 
105906 
Nonane Unknown 384 , 2.340 57 
 
96054 
Benzene, propyl- Unknown 440 , 4.030 91 
 
20249 
Cyclopropane, 1-heptyl-2-
methyl- 
Unknown 488 , 2.510 55 
 
54155 
130 
 
 
Name Type R.T. (s) 
Quant 
Masses 
Concentration Area 
Decane Unknown 496 , 2.350 56 
 
12393 
3-Octene, 2,6-dimethyl- Unknown 568 , 2.530 69 
 
20446 
Cyclopropane, 1-heptyl-2-
methyl- 
Unknown 584 , 2.580 69 
 
22771 
Undecane Unknown 592 , 2.410 57 
 
31578 
Bicyclo[2.2.2]oct-2-ene Unknown 656 , 4.370 80 
 
14337 
Cyclopropane, 1-heptyl-2-
methyl- 
Unknown 672 , 2.640 55 
 
17821 
Undecane Unknown 680 , 2.480 70 
 
3068.8 
Unknown 8 Unknown 752 , 2.200 57 
 
18077 
Cyclooctane, 1,4-dimethyl-, cis- Unknown 752 , 2.230 55 
 
19644 
Oxalic acid, allyl tridecyl ester Unknown 760 , 2.120 55 
 
32826 
6-Tridecene Unknown 800 , 2.070 55 
 
22250 
Tridecane Unknown 808 , 1.930 57 
 
14622 
Decane, 2,5,9-trimethyl- Unknown 840 , 1.960 57 
 
16889 
5-Dodecene, (E)- Unknown 840 , 1.990 55 
 
28671 
Hexadecane Unknown 872 , 1.950 57 
 
13271 
1-Trifluoroacetoxy-10-
undecene 
Unknown 872 , 1.990 55 
 
19411 
Oxalic acid, allyl hexadecyl 
ester 
Unknown 904 , 1.930 57 
 
8442.1 
Unknown 9 Unknown 912 , 3.400 91 
 
13611 
Oxalic acid, allyl tridecyl ester Unknown 928 , 1.980 57 
 
7625.8 
 
131 
 
 
 
Figure 29: 3D Image of 130417 post scrub 
 
 
Figure 30: Total ion chromatogram of 130417 post scrub 
The combination of fast GC technique with faster temperature programming, fast 
acquisition rate, and unique deconvolution algorithm allows accurate analysis of the 
samples. The total time for the analysis of samples is 18 min. The quantitation of the 
aromatics after the qualitative characterization is determined using the calibration 
standards. 
0
200
0
400
0
600
0
800
0
1000
100000
150000
200000
250000
300000
350000
400000
450000
500000
1st Time (s)
2nd T ime (s)
TIC
132 
 
 
By reviewing the results, the reproducibility of the quantified aromatic data in 
fuel and hydrocarbon samples was good within each method and the data were 
comparable by two methods, one dimensional and two dimensional gas chromatography. 
In 1D there was not a good separation of the deuterated compounds from their respective 
analytes even though they were identified based on their m/z ratio, but in 2D there was a 
distinct separation of the deuterated compounds from their respective analytes on 
secondary column by reducing the width and increasing the height of the peaks and 
moreover the linearity with the calibrated compounds and the reproducibility of the data 
appear to be better by 2D GC method than the 1D GC method. 
 From the data, we observed that the gasoline with different grades collected on 
different days contains benzene, toluene, ethylbenzene, cumene but does not have any 
styrene, or α- methylstyrene. The data were comparable by both the methods and are 
reproducible when they are analyzed on different days except in benzene. The difference 
in mass percent of benzene might be due to the collection of the samples from different 
places or it might be due to the evaporation of benzene which is highly volatile (samples 
were more than 30 days old). 
 Diesel does not contain any of the six aromatic compounds in it. Most of it has 
alkane and alkene derivatives in it especially decane and decene derivatives when 
analyzed qualitatively. 
 Pygas samples contain all the six aromatic compounds, even the styrene and α- 
methylstyrene which are not seen in gasoline. The presence of styrene derivatives in 
pygas samples might be due to their starting materials plastic, rubber from which they 
were made. 
133 
 
 
4.2 Inductively Coupled Plasma Mass Spectrometry (ICP- MS) 
The results and discussion are made on the basis of gasoline and diesel samples. 
A calibration curve for was constructed using the following concentrations: 0.5, 1.0, 3.0, 
10.0, 30.0 ppb in 3 % nitric acid. Five calibration standards of known concentration along 
with a blank were analyzed which generated a calibration curve for each element. The R
2 
(correlation coefficient)
 
value represents the correlation of data points on a straight line. 
A correlation of 1.000 represents that all the data points lie on the same straight line. Any 
deviation of the value from the equation of the line decreases the value significantly. 
In the Calibration Curves, the Y- axis represents the ICP signal in counts per 
second and the X- axis represents the concentration of individual elements. Calibration 
curves for vanadium, chromium, cobalt, and lead were prepared using the multi- element 
analysis mixture. The correlation coefficient and the equation of the line of each element 
were shown along with their respective calibration curves.  
 
Figure 31: Calibration curve of vanadium 
\f(x) = 8718.230*x + 60.000 
r = 1.000 
134 
 
 
 
Figure 32: Calibration curve of chromium  
f(x) = 13324.307*x + 570.014 
r = 1.000 
 
Figure 33: Calibration curve of cobalt 
f(x) = 25812.914*x + 40.000 
r = 1.000 
135 
 
 
 
Figure 34: Calibration curve of lead 
f(x) = 132275.793*x + 3495.509 
r = 0.997 
4.2.1 Elemental analysis of gasoline, diesel and pygas samples 
 A number of acid digestion procedures like nitric acid with hydrogen peroxide, 
sulfuric acid with hydrogen peroxide, nitric acid sulfuric acid mixture (1:3) with 
hydrogen peroxide, nitric acid hydrochloric acid mixture (1:3) with hydrogen peroxide 
and lithium metaborate fusion method were performed in order to dissolve the fuel and 
hydrocarbon samples. Of these, the lithium metaborate procedure is convenient and does 
not require the use of large amounts of strong acids and was selected as the method for 
preparation of the fuel samples. Elemental analysis of the dissolved fuel and hydrocarbon 
samples were performed using the calibration curves of their respective elements. Table 
74 shows the calculated concentration of the elements in gasoline, diesel and pygas 
samples in parts per million (PPM). The data obtained from ICP- MS is in parts per 
billion (ppb). To convert to content in the original sample, the values that are obtained are 
136 
 
 
blank subtracted and multiplied with the total volume that it was diluted (50) and then 
divided with the amount of sample that was digested (i. e., 0.5 g). The value that obtained 
was finally divided with 1000 to convert the parts per billion (PPB) to parts per million 
(PPM). 
4.2.2 Elemental analysis of gasoline, diesel and pygas samples 
Qualitative and quantitative determination of chromium, lead, vanadium, cobalt, 
zinc and copper in Polyflow, gasoline and diesel samples were performed using the 
calibration curves of their respective elements. Table 76 shows the calculated 
concentration of the elements in gasoline and diesel samples in Parts per million (ppm). 
 The data obtained from the ICP- MS is in ppb. The concentration obtained for the 
samples are blank subtracted and multiplied with the total volume that it was diluted (50) 
and then divided with the amount of sample that was digested (i. e., 0.5 g). The value that 
were obtained were finally divided with 1000 to convert the PPB to PPM.  
Gasoline samples contain chromium, vanadium and cobalt of all the elements that 
it was quantified. Diesel samples collected from two different places contain chromium, 
cadmium, lead, vanadium and cobalt in common when quantified against their respective 
standards. All the pygas samples contain chromium, lead, vanadium, cobalt in common 
but the Pygas samples, 130417 post scrub, 130313 post scrub, 130313 pyrogas scrub, 
130712- 1 3:00 PM, 130712- 2 4:25 PM and 130712 treated contains zinc in addition to 
the above mentioned elements. All the elements in gasoline, diesel and pygas samples 
were listed in table 76 along with their concentrations in PPM. 
137 
 
 
Table 74: Elements in different grades of gasoline, diesel and pygas samples (PPM) 
Analyte 
Gasoline 
super 
Gasoline 
Regular 
Marathon 
diesel 
Diesel 
pilot 
130417 Post 
scrub 
130313 Post 
scrub 
130313 Pyrogas 
scrub  
Chromium 0.31647 0.39468 0.565343 0.567006 0.735834 0.746404 0.836187 
Manganese 0 0 0 0 0 0 0 
Nickel 0 0 0 0 0 0 0 
Arsenic 0 0 0 0 0 0 0 
Selenium 0 0 0 0 0 0 0 
Silver 0 0 0 0 0 0 0 
Cadmium 0 0 0.000286 0.000297 0 0 0 
Lead 0 0 0.326776 0.328944 0.16731 0.158789 0.160489 
Vanadium 0.004917 0.00396 0.005676 0.004917 0.005511 0.005475 0.005234 
Cobalt 0.00132 0.00363 0.004523 0.004158 0.006567 0.006561 0.006963 
Zinc 0 0 0 0 0.087582 0.089334 0.08052 
Copper 0 0 0 0 0 0 0 
 
 
 
 
 
138 
 
 
Analyte 130712-1 3:00 
 
130712-2 4:25 
 
130719 11;00 
 
130719 12:30 
 
130719 1:45 pm 130712 Treated 
Chromium 0.899283 1.078506 1.153317 1.283898 1.383096 1.444311 
Manganese 0 0 0 0 0 0 
Nickel 0 0 0 0 0 0 
Arsenic 0 0 0 0 0 0 
Selenium 0 0 0 0 0 0 
Silver 0 0 0 0 0 0 
Cadmium 0 0 0 0 0 0 
Lead 1.193593 1.206942 1.043922 0.969243 0.976414 1.030161 
Vanadium 0.006831 0.005676 0.007194 0.009471 0.00759 0.007953 
Cobalt 0.004158 0.006402 0.008382 0.009273 0.009273 0.009834 
Zinc 0.344784 0.357905 0 0 0 0.086196 
Copper  0 0 0 0 0 0 
 
NOTE: Concentrations shown in table are in PPM 
 
 
 
 
 
 
 
139 
 
 
4.3 Nitrogen/ sulfur analyzer 
The stock solution for nitrogen sulfur determination is prepared based on mass by 
taking N, N- dimethyl aniline (0.1 g) and dibenzothiophene (0.1 g) in toluene (99.8 g) 
which is 1000 ppm. Calibration standards of 10 ppm, 50 ppm, 100 ppm, 300 ppm, 500 
ppm of N, N- dimethyl aniline and dibenzothiophene were prepared by adding 0.5 ml, 2.5 
ml, 5 ml, 15 ml, 25 ml of stock solution (1000 ppm) to a 50 ml volumetric flask 
respectively and finally diluting to 50 ml with toluene. The concentrations of nitrogen 
and sulfur in the diluted standards are listed in the table. 
Table 75: Nitrogen and sulfur concentrations in standards 
Stock dibenzothiophene and 
   
Nitrogen (PPM) Sulfur (PPM) 
10 PPM 1.155 1.740 
50 PPM 5.775 8.7 
100 PPM 11.55 17.40 
300 PPM 34.65 52.20 
500 PPM 57.75 87 
4.3.1 Nitrogen 
 The calibration curve for nitrogen was constructed using the following 
concentrations: 10, 50, 100, 300 and 500 ppm. Each standard was run in triplicate for  
reproducibility of the results. The calibration curve for nitrogen was shown in figure  and 
the linearity is good with a correlation coefficient (R
2
= 0.999510). A calibration curve for 
nitrogen was plotted by taking the nitrogen volume (amount of sample injected times the 
concentration) on x- axis and area on y- axis.  
140 
 
 
 
Figure 35: Calibration curve of nitrogen 
Equation of the line Y = 3625.8741x – 108.6783 
Correlation coefficient- 0.999510 
All the calibration standards including the blank were run in triplicate and the 
signal traces for the calibration standard are shown in figure 53. The traces correspond to 
three repetitive injections of a refine toluene sample that contained about 10, 50, 100, 300 
and 500 ppm N, N dimethyl aniline. The chromatogram demonstrates excellent 
sensitivity and selectivity. 
141 
 
 
 
Figure 36: Signal traces for samples containing different concentrations of nitrogen  
4.3.2 Sulfur: 
The calibration curve for sulfur was constructed using the following 
concentrations: 10, 50, 100, 300 and 500 ppm. Each standard was run in triplicate for  
reproducibility of the results. The calibration curve for nitrogen was shown in figure  and 
the linearity is good with a correlation coefficient (R
2
= 0.999988). A calibration curve for 
sulfur was plotted by taking the nitrogen volume (amount of sample injected times the 
concentration) on x- axis and area on y- axis.  
142 
 
 
 
Figure 37: Calibration curve of sulfur 
Equation of line Y = 5806.3238x – 13.5898 
Correlation Coefficient- 0.999988 
All the calibration standards including the blank were run in triplicate and the 
signal traces for the calibration standard are shown in figure 55. The traces correspond to 
three repetitive injections of a refine toluene sample that contained about 10, 50, 100, 300 
and 500 ppm dibenzothiophene. The chromatogram demonstrates excellent sensitivity 
and selectivity. 
 
143 
 
 
 
Figure 38: Signal traces for samples containing different concentrations of sulfur 
Sample Preparation: 
 All gasoline and diesel fuel sample are directly analyzed for nitrogen/ sulfur 
content whereas the Polyflow samples are diluted to 1/ 10 in toluene. Nitrogen and sulfur 
concentration were quantified with their respective calibration standards. The 
concentrations along with their relative standard deviation percentage in each of the 
samples were listed in the table. From the results listed in table 78, we can conclude that 
the pygas samples contain large amount of nitrogen and sulfur when compared to that of 
gasoline and diesel samples. Because of the presence of large amount of nitrogen and 
sulfur in pygas samples, we suggest that further treatment should be done for the removal 
of sulfur and nitrogen before material is suitable for fuel blending. 
144 
 
 
Table 76: Nitrogen and sulfur concentrations in gasoline, diesel and pygas samples 
(PPM) 
Sample 
Nitrogen Sulfur 
Concentration 
(PPM) 
RSD % 
Concentration 
(PPM) 
RSD % 
Distillation Standard 
  
1.24 1.92 0.29 7.33 
Gasoline Super 2.47 0.70 4.365 0.53 
Gasoline Regular 4.93 0.77 16.67 0.52 
Marathon diesel 12.13 0.22 8.40 0.41 
Diesel Pilot 8.87 1.15 6.59 1.52 
130417 Post Scrub 722.38 1.03 60.59 0.96 
130313 Post Scrub 467.42 0.48 43.66 0.86 
130313 Pyrogas 
 
836.32 0.12 98.11 0.35 
130719 11:00 AM 1476.20 0.38 83.42 0.45 
130719 12:30 PM 540.23 0.28 25.48 1.05 
130719 1:45 PM 844.65 0.36 51.48 1.79 
130712- 1 3:00 PM 2469. 17 0.18 46.02 1.54 
130712- 2 4:30 PM 1163.5 0.50 16.78 2.64 
130712 Treated 1997.05 0.26 38.46 0.86 
 
 
 
 
145 
 
 
4.4 Conclusion: 
 The characterization and quantitative determination of aromatic compounds, 
nitrogen, sulfur and trace metals in fuel and hydrocarbon samples were performed. The 
one dimensional and two dimensional gas chromatography measurements of majority of 
the quantified aromatic compounds in the fuel and hydrocarbon were comparable and 
reproducible. The gas chromatography method used for analysis was evaluated by 
running the samples in triplicate. One of the main reasons of running the samples by two 
dimensional gas chromatography is to completely separate the compounds from each 
other, to obtain a good peak shape and width over wide volatility range, and to provide up 
to a  ten fold increase in analyte detectability. The LECO Pegasus 4D GC x GC TOFMS 
provided a significant increase in chromatographic resolution for the most complex 
samples across a wide volatility range. Complete characterization of the gasoline, regular 
and pygas samples, including identification of several classes of compounds like 
aromatics, alkanes, alkenes and heterocyclic compounds is also easily achieved using the 
ascending temperature program with GC x GC TOFMS. The automated peak find 
algorithm in the ChromaTOF software locates all the peaks in the chromatogram, 
including those that coelute with other analytes in the chromatogram. The reproducibility 
of the results of the most complex samples like gasoline, diesel and pygas samples is 
high. 
The lithium metaborate fusion method was used for the determination of trace 
amount of elements in gasoline, diesel and pygas samples by ICP- MS. Trace amount of 
chromium, lead, vanadium and cobalt are present in gasoline, diesel and pygas samples, 
but the concentration of the element varies. Due to the complex nature of the gasoline, 
146 
 
 
diesel, pygas samples, a high temperature furnace with a nitrogen/ sulfur 
chemiluminescence detector had been used for measurement of nitrogen and sulfur. From 
the results, the pygas samples contain large amount of nitrogen and sulfur when 
compared to that of gasoline and diesel samples. The presence of large amount of 
nitrogen and sulfur in pygas samples, suggest that the pygas should be treated to remove 
sulfur and nitrogen hetero- atoms. 
In future study, it would be good to try changing different parameters on the GC 
like split ratios, temperature programming, modulation period and to try running the 
samples using an agitator on GC x GC TOFMS and look for any change in the results. 
Also using a microwave digestion for the sample preparation on ICP- MS should be 
studied. Finally running the sample by combustion ion chromatography (CIC) for the 
halide and sulfur should be performed to compare the sulfur results with that of sulfur 
analyzer. 
 
 
 
 
 
 
 
147 
 
 
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