Hydride Generation-Atomic Fluorescence Spectrometric Determination of Inorganic Arsenicin in Soil Samples with Microwave-assisted Extraction

A method has been established for the determination of inorganic arsenic in soils by hydride generation-atomic fluorescence spectrometry combined with microwave-assisted extraction.The microwave-assisted extraction operating conditions were optimized by the orthogonal test design combined with the mono-factor test.The interference from coexisting ions on inorganic arsenic determination was eliminated using ascorbic acid-thiourea-citric acid.The linear range of the calibration curve for inorganic arsenic is 0.25~40 μg/g.The detection limit is 0.05 μg/g for inorganic arsenic.The recovery of inorganic arsenic in soil samples was 92.9%～105.0% with precision of 0.3%RSD(n=11).Compared with the results obtained from the water bath extraction method,the microwave-assisted extraction method was time-saving and more efficient.The method has been successfully applied to the extraction and determination of inorganic arsenic in soil samples from different regions.