Determination of arsenic in soil extracts by flow-through anodic stripping coulometry

Flow-through coulometry was used for the determination of arsenic in soil extracts in 2 mol.dm-3 HCl solution. Arsenic(III) species were deposited on gold plated porous working electrodes and then galvanostatically stripped. The procedure was optimized and possible interferences were identified. The total As content was determined after a reduction step in a microwave oven with hydrazine hydrochloride. The detection limit was found to be 0.15 µg·dm-3 in the analyzed solution. A linear response range was achieved up to As concentrations of several mg·dm-3. The procedure was applied for the analysis of soil extract samples from three localities in Slovakia.