Determination of inorganic arsenic [As(III) plus As(V)] in water samples by microwave assisted distillation and hydride generation atomic absorption spectrometry

Inorganic arsenic was determined in samples of natural water from Region II of Chile, using a methodology consisting on microwave assisted distillatio n and hydride generation atomic absorption spectrometry (HG-AAS). The analy tical features of the method are as follows: detection limit, 5 mu g l(-1); precision (RSD), 5%; and recovery, 93 +/- 3% for As(III) and 95 +/- 9% for As(V). The inorganic arsenic concentrations varied within the range 0.95-1 3.08 mg l(-1). The concentrations of inorganic arsenic obtained by microwav e assisted distillation and HG-AAS, compared with the concentrations of As( III) + As(V) obtained by anion exchange chromatography coupled to HG-AAS, s howed no statistically significant differences. The use of microwave assist ed distillation and HG-AAS provides a simple, inexpensive way of isolating inorganic arsenic from water matrices that may otherwise cause interference s if analysed directly by HG-AAS.