Methods for Environmental Samples

The United States Environmental Protection Agency (EPA) requires the determination of important trace elements in a variety of environmental samples. Graphite furnace atomic absorption methods are recommended for some elements including As, Se, Cd, Pb, Tl, Sb, Ag, Be and Cr. Graphite furnace analyses can be difficult due to chemical and spectral interferences. Quantification in atomic absorption requires that for a given analyte mass the signal be identical in the reference standard and in the sample. Chemical interferences occur when sample matrix constituents alter the atomization efficiency of the analyte element resulting in a matrix dependent analyte signal. Chemical (or matrix) interferences can be minimized by the use of platform atomization techniques and appropriate matrix modifiers.