ATOMIC SPECTROMETRY HYPHENATED TO CHROMATOGRAPHY FOR ELEMENTAL SPECIATION - PERFORMANCE ASSESSMENT WITHIN THE STANDARDS, MEASUREMENTS AND TESTING PROGRAM (COMMUNITY-BUREAU-OF-REFERENCE) OF THE EUROPEAN-UNION

Hyphenated techniques coupling atomic spectrometry to chromatography h ave been developed within the past ten years for the determination of a wide variety of chemical elemental species (e.g., organotins, methyl mercury, alkyllead compounds), These techniques generally involve a su ccession of analytical steps such as extraction, derivatization, separ ation and detection which have to be carried out in such a way that th e speciation is not changed during the analytical process, The need fo r 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 interlabo ratory studies, These projects followed a stepwise approach for the ev aluation of different steps of the analytical methods used, e.g., simp le solutions to test the detection, cleaned extract to evaluate the se paration, 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 o r a laboratory to be detected and removed, This paper presents an over view of organizational aspects of interlaboratory studies and gives an account of discussions of possible errors occurring in speciation ana lysis, Particular emphasis is placed on the results obtained by atomic spectrometric techniques hyphenated to chromatography as applied to t he determination of tributyltin, methylmercury, trimethyllead, arsenic and selenium species.