Quantitation of Toxic Elements in Various Water Samples by Multi-element Graphite Furnace Atomic Absorption Spectrometry

Abstract

A simultaneous, multi-element graphite furnace atomic absorption spectrometric method was developed for the determination of several toxic elements (As, Cd, Cr, Cu, Pb, and Se) in various water samples (snow, tap, well, and highly mineralized). The transversely heated graphite atomizer (THGA) with Zeemaneffect background (BG) correction was applied throughout the study. Two sets of analytes, i.e., Cr-Cu and As-Cd-Pb-Se, were simultaneously determined by using standard and end-capped THGA tubes, respectively. During the drying and pyrolysis stages of the furnace heating program, 5% H 2 was added to the internal furnace gas (Ar) in order to assist the action of the chemical modifiers, and to provide a prolonged lifetime of the THGA tubes.The effect of chloride and sulfate interferents as well as the composition/amount of the Pd-Mg modifier was studied. Addition of SO 4 2matrix even at a relatively low concentration (500 mg/L) caused a more significant decrease in recovery than with the Clmatrix, for instance, for As, Pb and Se, by applying low modifier amounts (5 µg Pd + 0.5 µg Mg).