Determination of arsenic in food samples by hydride generation - Atomic absorption spectrometry

A method for the determination of trace amounts of arsenic in food samples using flow injection analysis and atomic absorption spectrometry with hydride generation (FI-HG AAS) was developed. The parameters of the flow injection system and the hydride generation were optimized with respect to reagent concentrations, atomization temperature, injection volume, reaction coil length and carrier flow rate. The limits of detection and quantification were 0.34 mug L-1 and 1.2 mug L-:1, respectively, and the analytical curve is linear up to 30.0 mug L-1 arsenic. The relative standard deviation for 12 replicates varies between 5% for 4.0 mug L-1 As and 1.8% for 30.0 mug L-1 As, with an injection frequency of up to 135 h(-1). Interferences from Ni(II), Cu(II), Fe(III), Cr(III), Mo(II), Bi(III), Se(IV), Se(VI), Sb(III) and Sb(V) could be masked with a mixture of ascorbic acid-KI in a 5.0 mol L-1 HCl solution. The accuracy of the proposed method was evaluated by using certified reference materials of biological samples, and the method was used to determine the content of arsenic in fish and coffee beans.