Quantification of total arsenic in groundwater by HG-AAS using low acid concentration and L-cysteine

Abstract: A simple and inexpensive analytical method has been developed and applied for the quantification of total arsenic (arsenite + arsenate + monomethylarsonic acid + dimethylarsinic acid) in groundwater samples collected from various locations in United Arab Emirates. The method utilized HG-AAS and L-cysteine (as a pre-reducing agent) in low concentrations of nitric acid. The optimised experimental conditions were: 0.04 -0.06 M HNO 3 , 2% Lcysteine, and 15 minutes delay time after adding L-cysteine. The method's detection limit is 0.2 µg/L. The accuracy of the method has been checked using a CRM and spike recovery and found to be better than 83% with low standard deviations. The determined total arsenic concentration in the collected water samples was less than 5 µg/L. One advantage of this method over other comparable methods is that, it avoids the use of high acid concentrations. It is also suitable for routine batch analysis