DEVELOPMENT OF A MULTIELEMENT HYDRIDE GENERATION INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY PROCEDURE FOR THE SIMULTANEOUS DETERMINATION OF ARSENIC, ANTIMONY AND SELENIUM IN WATERS

A multi-element hydride generation-inductively coupled plasma mass spe ctrometry (HG-ICP-MS) method for the simultaneous determination of ars enic, antimony and selenium in water matrices has been developed. The method involves an off-line pre-reduction procedure for the reduction of Se-VI to Se-IV by HCl, combined with an on-line reduction of As-V a nd Sb-V to the trivalent state with thiourea and generation of the hyd rides, Analytical characteristics include detection limits of 0.08 ng g(-1) As, 0.06 ng g(-1) Sb and 0.10 ng g(-1) Se, linearity of four ord ers of magnitude and short and long term reproducibility of between 8 and 12%, Results from four reference water samples for As, Sb and Se s howed data which were all within 10% of the target values, Interferenc es were minimal for As and Sb, whereas Cu2+, and to a lesser extent Ni 2+ and Cd2+, caused signal suppression effects on Se, Advantages over an alternative, single element, HG-AFS technique include speed of anal ysis (by a factor of two) and elimination of the conflicting chemistry requirements, traditionally found with sequential single element hydr ide generation methods.