Development of a Multi-element Hydride Generation–Inductively Coupled Plasma Mass Spectrometry Procedure for the Simultaneous Determination of Arsenic, Antimony and Selenium in Waters

Abstract

A multi-element hydride generation–inductively coupled plasma mass spectrometry (HG–ICP-MS) method for the simultaneous determination of arsenic, 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 and Sb ^V to the trivalent state with thiourea and generation of the hydrides. 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 orders of magnitude and short and long term reproducibility of between 8 and 12%. Results from four reference water samples for As, Sb and Se showed data which were all within 10% of the target values. Interferences were minimal for As and Sb, whereas Cu ²⁺ , and to a lesser extent Ni ²⁺ and Cd ²⁺ , caused signal suppression effects on Se. Advantages over an alternative, single element, HG–AFS technique include speed of analysis (by a factor of two) and elimination of the conflicting chemistry requirements, traditionally found with sequential single element hydride generation methods.