Atomic Absorption Spectrometric Determination of Arsenic

The official AOAC method for arsenic in feeds has been adapted to an atomic absorption spectrophotometric technique in which the arsenic trapped in the absorbing solution is aspirated into the flame. Values as low as 0.5 μg As/g can be measured in a 10 g sample. A modified digestion procedure is described. A second method is described for the determination of submicrogram quantities of arsenic whereby the arsine gas is generated into a plastic bag and introduced directly into the flame. Air-acetylene fuels are utilized, requiring no alterations in the nebulizer and mixing chamber. Sensitivity attained from a 10 g sample is 0.1 μg As/g. Results of various biological matrices, which were determined by the AOAC method and the 2 described methods, compare favorably.