DETERMINATION OF ARSENIC IN ENVIRONMENTAL AND BIOLOGICAL SAMPLES BY FLAW INJECTION INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY

A simple and very inexpensive ill situ nebulizer-hydride generator was used with inductively coupled plasma mass spectrometry (ICP-MS) for t he determination of arsenic in environmental and biological samples, T he application of hydride generation (HG)-ICP-MS alleviated the spectr al interferences and sensitivity problems of arsenic determinations en countered when conventional pneumatic nebulization is used for sample introduction, The sample was introduced by how injection to minimize d eposition of solids on the sampling orifice, The arsenic in the sample was reduced to As(III) with L-cysteine before being injected into the HG system. A detection limit of 0.003 ng ml(-1) was obtained for arse nic, The method has been successfully applied to the determination of arsenic in National Research Council of Canada reference materials, CA SS-2 (Nearshore Seawater Reference Material for Trace Metals), NASS-3 (Open Ocean Reference Material for-Trace Metals) and SLRS-2 (Riverine Water Reference Material for Trace Metals), and in National Institute of Standards and Technology, Standard Reference Material 2670, Toxic M etals in Freeze-Dried Urine, Precision was less than 5% and analysis r esults were within 6% of the certified values for all determinations.