A Modified Routine Analysis of Arsenic Content in Drinking-water in Bangladesh by Hydride Generation-Atomic Absorption Spectrophotometry

M.A. Wahed, Dulaly Chowdhury, Barbro Nermell, Shafiqul Islam Khan, Mohammad Ilias, Mahfuzar Rahman, Lars Åke Persson, Marie Vahter

Abstract


The high prevalence of elevated levels of arsenic in drinking-water in many countries, including Bangladesh, has necessitated the development of reliable and rapid methods for the determination of a wide range of arsenic concentrations in water. A simple hydride generation-atomic absorption spectrometry (HG-AAS) method for the determination of arsenic in the range of µg/L to mg/L concentrations in water is reported here. The method showed linearity over concentrations ranging from 1 to 30 µg/L, but requires dilution of samples with higher concentrations. The detection limit ranged from 0.3 to 0.5 µg/L. Evaluation of the method, using internal quality-control (QC) samples (pooled water samples) and spiked internal QC samples throughout the study, and Standard Reference Material in certain lots, showed good accuracy and precision. Analysis of duplicate water samples at another laboratory also showed good agreement. In total, 13,286 tubewell water samples from Matlab, a rural area in Bangladesh, were analyzed. Thirty-seven percent of the water samples had concentrations below 50 µg/L, 29% below the WHO guideline value of 10 µg/L, and 17% below 1 µg/L. The HG-AAS was found to be a precise, sensitive, and reasonably fast and simple method for analysis of arsenic concentrations in water samples.

Key words:   Hydride generation-atomic absorption spectrophotometry; Arsenic; Tubewells; Drinking-water; Bangladesh

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