SEPARATION AND PRECONCENTRATION OF TRACE ORGAN ARSENIC SPECIES IN WATER SAMPLES BY ION EXCHANGE CHROMATOGRAPHY

A simple and sensitive method for the separation and determination of monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA)is presented. The separation is achieved by cation exchange chromatography. MMA and DMA are determined by neutron activation analysis of the fractions collected. The recoveries of MMA and DMA are (96±2)% and (103±3)%, their relative standard deviations are 6% and 3%,respectively.