Atomic spectrometry hyphenated to chromatography for elemental speciation: performance assessment within the Standards, Measurements and Testing Programme (Community Bureau of Reference) of the European Union

Abstract

Hyphenated techniques coupling atomic spectrometry to chromatography have been developed within the past ten years for the determination of a wide variety of chemical elemental species (e.g., organotins, methylmercury, alkyllead compounds). These techniques generally involve a succession of analytical steps such as extraction, derivatization, separation and detection which have to be carried out in such a way that the speciation is not changed during the analytical process. The need for an assessment of method performance has led the Community Bureau of Reference programme of the European Commission (now renamed Standards, Measurements and Testing Programme) to organize a series of interlaboratory studies. These projects followed a stepwise approach for the evaluation of different steps of the analytical methods used, e.g., simple solutions to test the detection, cleaned extract to evaluate the separation, spiked samples to test the extraction and natural samples to evaluate the whole analytical procedure. These collaborative projects allowed most of the sources of errors related to either a technique or a laboratory to be detected and removed. This paper presents an overview of organizational aspects of interlaboratory studies and gives an account of discussions of possible errors occurring in speciation analysis. Particular emphasis is placed on the results obtained by atomic spectrometric techniques hyphenated to chromatography as applied to the determination of tributyltin, methylmercury, trimethyllead, arsenic and selenium species.