Simultaneous determination of arsenic, selenium and antimony by hydride generation/ICP-MS

The authors have developed an analytical method for arsenic, selenium and antimony in water by using hydride generation (HG) coupled with ICP-MS. The method provides simultaneous analysis with high sensitivity and precision. After samples had been decomposed with perchloric acid and nitric acid, the target metals were pre-reduced with HCl and potassium iodide, , and then introduced into HG/ICP-MS. Interference of 40Ar35Cl caused by HCl with measurement of 75As was negligible. 72Ge is a useful internal standard for HG/ICP-MS, because it can correct any drift of the sensitivity of ICP-MS. The instrumental detection limits of the method were as low as 10 ng/l; these values are one-one hundredth as those of HG/ICP-AES. The overall recoveries of sea-water and waste water samples to which the metals were spiked to make 1 μg/l of each were more than 80%; the relative stadard deviations were less than 10%. Applying the method to seawater, the authors found the three metals to have the same concentration levels as those published.