Microwave assisted reduction of Se VI to Se IV and determination by HG/FI-ICP/MS for inorganic selenium speciation

Abstract

Speciation of inorganic selenium using hydride generation method is a widespread analytical method nowadays. However, a reduction step of Se VI to Se IV is necessary as the hydride-forming species is HSeO 3 − (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 μl) respectively have been achieved. This method has been validated by participating in a European certification exercise for inorganic Se speciation in aqueous solutions.