Simultaneous determination of arsenic, antimony and selenium in aqueous matrices by electrothermal vaporization inductively coupled plasma mass spectrometry

A method for the simultaneous determination of As, Se and Sb in aqueous matrices by ETV-ICP-MS has been developed, Complex interactions between the analytes and various chemical modifiers are described. A mixed modifier of Pd(NO3)(2)-Ni(NO3)(2) was finally selected for quantitative multi-element analysis, Criteria of merit of the proposed method include a 0-100 ng g(-1) linear range for As and Sb and 0.5-100 ng g(-1) for Se. Internal standardisation using Te was used to help produce repeatability of 3.9% for As, 6.9% for Se and 2.1% for Sb at the 1 ng g(-1) level. Detection limits of 0.03, 0.08 and 0.01 ng g(-1) for As, Se and Sb, respectively, are routinely achievable. The accuracy of the proposed method was demonstrated with the analysis of several reference waters. A severe negative interference on Se by high HCl concentrations could be overcome with the use of a Pd(NO3)(2)-Mg(NO3)(2)-ascorbic acid chemical modifier.