On-line pre-reduction of pentavalent arsenicals by thioglycolic acid for speciation analysis by selective hydride generation-cryotrapping-AAS
Abstract
An improvement of current method of selective hydride generation based on pre-reduction for differentiation of tri- and pentavalent arsenicals is described, applied for the oxidation state specific speciation analysis of inorganic, mono-, di- and trimethylated arsenicals with minimum sample pretreatment using atomic absorption spectrometry with the muitiatomizer. The preconcentration and separation of arsine, methylarsine, dimethylarsine and trimethylarsine are then carried out by means of cryotrapping.