Elemental analysis of sediment cores from Mahoning Valley Lakes by inductively coupled plasma-atomic emmision spectroscopy

Abstract

The Center for Environmental Studies at Youngstown State University has been investigating several of the lakes in the Mahoning Valley. The lakes are being tested to see if there has been any affect to the lakes physiological activities due to the presence of heavy metals. The lakes analyzed in this study were Pine, Evan's, and Girard. One sediment core was taken from each lake and freeze-dried for later analysis. The samples were digested using the EPA Method 3051 Microwave Assisted Acid Dissolution. The acid used to extract the metal ions was doubly-distilled 6M Nitric acid. The digestion produced a solution which could be analyzed by Inductively-Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES). ICP-AES is a technique which utilizes the characteristic wavelength of metals to determine the metal ion content in solutions. Sixteen heavy metals were determined for each sample. They were Al, Ba,Be, Cd, Ca, Cu, Fe, Pb, Mg, Mn, K, Na, Ti, V, Zn. The instrument used for analysis was an ARL model 3410 ICP spectrometer. Several other metals were considered for testing but due to the lack of sensitivity in the ICP, the metals were left to be determined in another study by a different method.