DETERMINATION OF ANIONIC, NEUTRAL, AND CATIONIC SPECIES OF ARSENIC BYION CHROMATOGRAPHY WITH ICPMS DETECTION IN ENVIRONMENTAL-SAMPLES

Ion chromatographic methods developed to separate either cationic, neu tral, and anionic arsenic species or soluble and suspended arsenic spe cies were successfully used in DORM-2 standard reference material and in water samples of environmental interest. The most effective separat ion of the analytes within 10 min was achieved with a nitric acid grad ient elution using a strong anion-exchange stationary phase with addit ional capacity for hydrophobic interactions (IonPac AS7). The elementa l-specific detection mode allows the sensitive determination of the ar senic species in the submicrogram per liter range. The calibration res ults were compared with those obtained by an alkaline water-methanol m ixed eluent combined with a weak anion-exchange column (IonPac AS4A-SC ). Differences in sensitivities were eclipsed by the low level of the baseline and the noise when using nitric acid. The gradient method was used to determine arsenic species in highly ferrous/ferric-contaminat ed leachates of lignite spoil. The companion elements underwent parall el screening to explain the interactions of arsenic species with the m ajor elements.