Electrothermal atomic absorption spectometry to determine As, Cd, Cr, Cu, Hg, and Pb in soils and sediments: a review and perspectives.

Abstract

Environmental pollution from trace elements has been increasing in recent decades and has become an important concern for environmental agencies. The trace elements arsenic, cadmium, chromium, copper, mercury, and lead are among the elements that cause the greatest environmental impact and carry the highest risk to human health. Electrothermal atomic absorption spectrometry (ETAAS) has long been employed in trace element determination. In the last few years the main constraints of spectroscopy absorption methods have been overcome. These advances have increased the possibilities and the utility of ETAAS for trace element determination at μg L−1 levels in difficult matrices such as soils and sediments, giving greater accuracy and precision, lower economic cost, and easier sample pretreatment than other methods. The main advances come from sample manipulation for matrix destruction and preconcentration, the use of new lab-on-valve FIA systems, the solid sampling, the use of new, more efficient modifiers and in situ trapping methods for analyte stabilization and pre-concentration, and the progress in the capacity to control the atomization temperature and to correct background spectral interferences. All of them have permitted an improvement in the sensitivity, decreasing the detection limits and manipulation process, and increasing the accuracy and precision of the analyses.

Moreover, the new technology in the optic and detector systems have given rise to high-resolution continuum source ETAAS (HR-CS ETAAS) spectrometers that solve most of the constraints presented by the more conventional line source ETAAS (LS ETAAS) spectrometers. HR-CS ETAAS enables a rapid detection of several elements at once, facilitates direct determination from solid sampling, and reduces the matrix interferences and background noise. Here we give an overview of the recent advances and the different possibilities of using ETAAS, drawing on studies from the last decade on methods to analyze As, Cd, Cu, Hg, and Pb in soils and sediments.