SIMULTANEOUS DETERMINATION OF FOUR SPECIES (As(III), As(V), MONOMETHYLARSONIC AND DIMETHYLARSONIC) IN TUBE WELL WATER BY HPLC-ICP-MS IN CHUYEN NGOAI, CHAU GIANG COMMUNE, DUYTIEN DICTRICT, HANAM PROVINE

Abstract

    Simultaneous determination of four arsenic species (arsenite, arsenate, monomethylarsonicacid and dimethylarsonic acid) was well developed and validated. The Anion exchangeseparation of As(III), As(V), DMA and MMA was accomplished on a Hamilton PRP - X100column using 12.5 mM (NH4)2HPO4 (pH= 8.5 adjusted by amonium hydroxide) solutioncontaining 3 % v/v of methanol as the mobile phase. The arsenic species were detected anddetermined by ICP-MS. The concentrations of arsenic in the two villages (Chuyen Ngoai,Chau Giang) in Ha Nam province in northern Vietnam significantly exceeded the Vietnamesedrinking water standard for arsenic (10 μg/L) with average concentrations of 510 and 118μg/L on the dry season , 359 and 90 μg/L on the rainy season , respectively. According to theresults of the arsenic speciation testing, the predominant arsenic species in the groundwaterexisted as arsenite [As(III)].This page was analyzed 200 samples ground water in Duy TienDistrict, Ha Nam Province.

Keywords: As(III), As(V), MMA, DMA, HPLC, ICP-MS, Duy Tien District, Ha Nam Province.