Direct analysis of methylated trivalent arsenicals in mouse liver by hydride generation-cryotrapping-atomic absorption spectrometry

Growing evidence suggest that the methylated trivalent metabolites of inorganic arsenic (iAs), methylarsonite (MAsIII) and dimethylarsinite (DMAsIII), contribute to adverse effects of iAs exposure. However, the lack of suitable methods has hindered the quantitative analysis of MAsIII and DMAsIII in complex biological matrices. Here, we show that hydride generation-cryotrapping-atomic absorption spectrometry can quantify both MAsIII and DMAsIII in livers of mice exposed to iAs. No sample extraction is required, thus limiting MAsIII or DMAsIII oxidation prior to analysis. The limits of detection are below 6 ng As/g of tissue, making this method suitable even for studies examining low exposures to iAs.