Determination of arsenic in chicken feed by hydride generation atomic absorption spectrometry after pre-concentration with polyurethane foam.

A pre-concentration procedure with solid-phase extraction was developed for the determination of arsenic (As) in chicken feed using hydride generation atomic absorption spectrometry (HG-AAS). The procedure was based on the sorption of As(III) ions as complexes with ammonium pyrrolidine dithiocarbamate onto a mini-column packed with polyurethane foam. After pre-concentration, the As was removed from the mini-column by acid solution, and the analyte content in the eluate was measured by HG-AAS. The following main experimental conditions were established: adjustment of the As solution pH with 0.05 mol l⁻¹ HCl, 2.88 × 10⁻³ mol l⁻¹ complexing agent concentration and 6.0 mol l⁻¹ eluting hydrochloric acid concentration. The proposed method produced an enrichment factor of 67, with 0.050 and 0.165 µg g⁻¹ limits of detection and quantification, respectively. The procedure was applied to the determination of As content in two types of chicken feed using the proposed procedure and atomic absorption spectrometry with electrothermal atomisation (ETAAS). The t-test indicated that the results were not significantly different at a confidence level of 95%.