High performance liquid chromatography—atomic fluorescence spectrometric determination of arsenic species in beer samples Original Research Article

A method has been developed for the direct determination of As(III), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA) and As(V) in beers by hydride generation—atomic fluorescence spectrometry after separation of arsenic species by high performance liquid chromatography. Compounds were separated by anion-exchange chromatography with isocratic elution using KH2PO4/K2HPO4 as mobile phase with elution times of 1.67, 2.08, 6.52 and 10.72 min for As(III), DMA, MMA and As(V), respectively. Parameters affecting the hydride generation of all arsenic species were studied and the best conditions were established as a reaction coil of 150 cm, for a sample injected volume of 100 μl, a 4.0% (m/v) solution of sodium tetrahydroborate and 2.0 mol l−1 hydrochloric acid with flow rates of 2.7 and 1.7 ml min−1, respectively and a flow rate of 500 ml min−1 for the argon carrier gas. Under the best experimental conditions, the detection limit was found to be 0.12, 0.20, 0.27 and 0.39 μg l−1 for As(III), DMA, MMA and As(V), respectively. The relative standard deviation for eight independent determinations varied from 3.9 till 8.9% for species considered at a concentration level of 10.0 μg l−1. Recovery and comparative studies evidenced that the method is suitable for the accurate determination of arsenic species in water and beer samples.