High-performance liquid chromatography hydride generation atomic fluorescence spectroscopic determination of arsenic species in water

A method was developed for the determination of arsenite (As-III), monomethylarsonate (MMAs), dimethylarsinate (DMAs), arsenate (As-v) from waters by using ion-pair chromatography hydride generation and atomic fluorescence spectrometry. A C-18 bonded silica column modified by didoctyldimethylammonium bromide (DDAB) was used for separation. The effect of phosphate and methanol content of the eluent on the separation was investigated. The influence of five metals on hydride generation efficiency was tested. The optimal hydrogen chloride and sodium borohydride quantity for hydride generation was determined. The detection limit of the developed method, by using a 250-mm(3) loop, was 0.4 ng/cm(3) for As-III, 0.8 ng/cm(3) for DMAs, 0.6 ng/cm(3) for MMAs and 1.2 ng/cm(3) for As-v. The responses for all species tested were linear in 10-3000 ng/cm(3) range.