Determination of As and Se in seawater by flow injection vapor generation ETV-ICP-MS

Arsenic and selenium (IV) were determined in seawater following hydride generation (HG) by reaction with NaBH4 in an automated flow injection system. The hydrides were trapped on reduced palladium in a graphite furnace (ETV) and subsequently vaporized into an ICP for MS detection. This HG-ETV-ICP-MS approach afforded blank-limited absolute detection limits of 7 pg for As and 70 pg for Se, using 0.5 and 10 mL sample volumes, respectively, permitting their determination in samples of NASS-4 and NASS-5 seawater reference material. Precision of determination was 2.5% RSD for As at 1 mu g/L and 10% for Se at 20 ng/L. Sample throughput was 8/h for As and 5/h for Se with interference-free quantitation of samples with the use of a standard calibration curve.