Speciation of arsenic in ground water samples: A comparative study of CE-UV, HG-AAS and LC-ICP-MS

The performance of capillary electrophoresis-ultraviolet detector (CE-UV), hydride generation-atomic absorption spectrometry (HG-AAS) and liquid chromatography-inductively coupled plasma mass spectrometry (LC-ICP-MS) have been compared for the speciation of arsenic (As) in groundwater samples. Two inorganic As species, arsenite (As III), arsenate (As V) and one organo species dimethyl arsenic acid (DMA) were mainly considered for this study as these are known to be predominant in water. Under optimal analytical conditions, limits of detection (LD) ranging from 0.10 (As III, AsT) to 0.19 (DMA) μg/l for HG-AAS, 100 (As III, DMA) to 500 (As V) μg/l for CE-UV and 0.1 (DMA, MMA) to 0.2 (As III, As V) μg/l for LC-ICP-MS, allowed the determination of the above three species present in these samples. Results obtained by all the three methods are well correlated ( r 2 = 0.996*** for total As) with the precision of