Speciation of Sb(III) and Sb(V) by hydride generation high-resolution ICP-MS combined with prereduction of Sb(V) with L-cysteine

A method of hydride generation inductively coupled plasma mass spectrometry combined with the pre-reduction of antimony(V) with L-cysteine was establi shed for the simultaneous speciation of inorganic antimony(III) and antimon y(V) species in water. It was proved that ppt levels of antimony(V) can be reduced linearly to antimony(III) with L-cysteine within 6 minutes. Antimon y(III) in solution was determined twice after 2 and 6 minutes' reaction tim e, respectively. The concentrations of antimony(III) and antimony(V) were o btained, respectively, by a relationship between the antimony(V) concentrat ion and the antimony(III) concentration, determined after 6 minutes, as wel l as the difference of two antimony(III) concentrations, determined after 2 and 6 minutes, respectively. Detection limits of the method for Sb(III) an d Sb(V) were 4.2 ng/L and 17 ng/L, respectively. The relative standard devi ation for ten determinations of a solution containing 100 ng/L Sb(V) was 11 .0% and for a solution containing 100 ng/L Sb(III) it was 9.04%. The method nas finally applied to determine antimony(III) and antimony(V) in Aragawa river water samples taken near Tokyo Bay. Recoveries of the method were bet ween 94-113% for Sb(III) and 91-111% for Sb(V), respectively.