Determination of arsenic in a nickel based alloy using a microwave-digestion procedure and a continuous flow hydride generation atomic absorption system incorporating on-line matrix removal

Abstract

A continuous flow hydride generation system incorporating a micro-column of strong cation-exchange material (SCX) was used in conjunction with flame heated quartz tube atomic absorption spectrometry for the determination of arsenic in a nickel based alloy. The system is capable of on-line matrix removal of nickel, which would cause severe depression of the arsenic signal. The resulting matrix stripped solution allowed hydride generation of arsenic to be achieved interference free. The columns were regenerated when necessary by using 1 M HCl. The procedure was successfully applied to a standard reference nickel based alloy (BCS 346) and the accuracy assessed through a recovery experiment for a 10 p.p.b. sample. The system was found to have a limit of detection of 1.3 ng and an RSD of 3.0%.