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), mon omethylarsonate (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 did octyldimethylammonium bromide (DDAB) was used for separation. The effe ct of phosphate and methanol content of the eluent on the separation w as investigated. The influence of five metals on hydride generation ef ficiency was tested. The optimal hydrogen chloride and sodium borohydr ide quantity for hydride generation was determined. The detection limi t 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/c m(3) for As-v. The responses for all species tested were linear in 10- 3000 ng/cm(3) range.