Determination of arsenic chemical species in rice grains using high-performance liquid chromatography coupled to hydride generator with atomic fluorescence detector (HPLC-HG-AFS)

Abstract The objective of this work is the validation and implementation of an analytical method for the determination of arsenic chemical species in rice grain samples using High-performance liquid chromatography coupled to a hydride generator with atomic fluorescence detector (HPLC-HG-AFS). The extraction protocol developed was based on HNO3 0.28 M (90°C, 2 hours), microwave-assisted. The results showed recovery percentages of arsenite (As (III)) (99-101%), arsenate (As (V)) (91-96%), dimethylarsinic acid (DMA) (92-102%) and monomethylarsonic acid (MMA) (94-97%). The precision of the method presented coefficients of variation lower than 7% and 8% for repeatability and reproducibility respectively. The detection limits were 2.5, 3.75, 7.5 and 4.0 μg Kg-1 for As (III), As (V), DMA and MMA respectively. The proposed methodology is reliable for the quantification of As species, because they are conserved during the extraction. The extraction protocol developed was based on Microwave-assisted acid extraction. This methodology offers good sensitivity, precision, accuracy, detection and quantification limits. It was successfully applied to determination of arsenic chemical species in rice grains.