Simultaneous determination of neutral, anionic and cationic compounds within one chromatographic run using an inductively coupled plasma mass spectrometer as element-specific detector

Two simple methods for the simultaneous separation of anionic and cationic arsenic species in a single injection were developed. One method was a dual column system connected with anion and cation exchange columns; the other was a dual mode system. The dual mode system was a combination of ion exclusion and cation exchange modes. The cation exchange resin, functionalized by dicarboxylic acid, was used for the dual mode column. Separation conditions for the two separation methods were optimized for eight arsenic species. The eight arsenic standards were completely separated within 40 min in both methods. On the dual column system, a good reproducibility (peak area reproducibility was 5% and under) for arsenic species was obtained by applying the column switching method, although the retentions of anionic arsenic species did fluctuate by interference of strong adsorptive anions, Inductively coupled plasma mass spectrometry as an element-selective detector was used. Detection limits for the eight arsenic compounds ranged from 0.1 to 0.71 mu gAsdm(-3), and reproducibility (relative standard deviation, n = 8) ranged from 2.4 to 8.0% at 0.01mg As dm(-3). The simultaneous separation methods developed were applied to the determination of arsenic species in human and rat urine. Good agreement on the quantified values by the two separation methods was obtained for all arsenic species in the urine samples. Copyright (C) 2001 John Wiley & Sons, Ltd.