Microwave assisted reduction of SeVI to SeIV and determination by HG/FI-ICP/MS for inorganic selenium speciation

Speciation of inorganic selenium using hydride generation method is a widespread analytical method nowadays. However, a reduction step of Se-VI to Serv is necessary as the hydride-forming species is HSeO3- (oxydation state + IV). This paper describes the development of a batch assisted microwave system allowing a rapid (< 5 min) conversion of Se-VI to Se-IV. Hydride generation is performed by a flow injection system and detection by ICP/MS. Detection limits of 6 and 8 pg for Se-IV and for Se-VI (by using a sample loop of 200 mu l) respectively have been achieved. This method has been validated by participating in a European certification exercise for inorganic Se speciation in aqueous solutions. (C) 1998 Elsevier Science B.V.