Quantification of four arsenic species in dried seafood <i>via</i> pressure tank-assisted extraction with HPLC-AFS

A method for the rapid separation and detection of dimethylarsenate (DMA), arsenite [As(iii)], monomethylarsenate (MMA), and arsenate [As(v)] was developed. This method combined high performance liquid chromatography with atomic fluorescence spectrometry (HPLC-AFS) <i>via</i> pressure tank-assisted extraction. Key parameters, including extraction temperature, extraction time, and extraction liquid concentration, were systematically investigated. Through orthogonal testing of the three factors at three levels, the optimal extraction conditions were identified as a nitric acid solution concentration of 1%, an extraction temperature of 150 °C, and an extraction time of 75 min. The results demonstrated that the four arsenic species could be completely separated within 6 min. Good linear relationships were observed in the concentration range of 1.00-100.0 μg L^-1 for all species, with detection limits ranging from 0.21 to 0.85 μg L^-1. The recoveries were between 88.6% and 103%, with relative standard deviations ranging from 1.4% to 4.8%. The method was successfully applied to detect the concentrations of arsenic species in dried seafood products, and it yielded satisfactory results. Moreover, the total arsenic concentration was quantified using atomic fluorescence spectrometry after wet digestion. The total concentration of arsenic in the samples was between 4.22 mg kg^-1 and 24.4 mg kg^-1, and the extraction efficiency, calculated as the percentage of the total arsenic species content extracted by the method to the total arsenic concentration, ranged from 1.35% to 13.5%. Notably, the inorganic arsenic levels in the analyzed samples were below the established safety limits.