Investigations On The Solvent-extraction And Quantification Of Arsenic Species In Seafoods

The acute and chronic poisoning induced by arsenic are demonstrated to have serious effect on the the survival and health of human beings, and then some arsenic species have been labelled as carcinogens by the International Cancer Research Center. The toxicity of arsenic is closely related to its species and the common toxicity order of arsenic species is as following:AsH3> As(III)> As2O3> As(V)> organic arsenic species> elemental arsenic. Inorganic arsenic is proved to be carcinogenic and teratogenic, while the toxicity of organic arsenic is much lower.In the present work, the mixture of methanol, malonic acid,1-butane sulfonate, tetramethyl ammonium hydroxide with water at different ratios were used for the pre-extraction of total arensic from seafoods. Under the optimal conditions, pre-extraction efficiencies higher than92%are achievevd for all of the four tested solvents. At the same time, no species conversion take place during the solvent-extraction process, suggesting the efficient extraction of arensic species.An graphite furnace atomic absorption spectrometry quantification procedure was also developed for the determination of As(III), after the separation/preconcentration by dispersive liquid-liquid microextraction. The experimental parameters governing the perofmance were investigated. Under the optimal conditions, an enrichment factor of98.7was obtained. As(III) in the range of0.05～0.80μg L’1could be determined by the developed method, with a detection limit of2.9ng L-1(3a, n=9). The precision deduced to be5.6%for0.10μg L-1of As(III)(n=9). The procedure was validated by analyzing arsenic in certified reference materials (GBW09101Trace Elements in Human hair and GBW10010Trace Elements in Rice) and the results were consistent with the certified values. The contents of As(Ⅲ) in a series of water samples and the extactant of seafoods including kelp, laver and hijiki, which was extracted by the above-mentioned methanol-extraction procedure, were also determined and satisfactory spiking recoveries were obtained.