AFS Determination of Arsenic, Antimony and Mercury in Leather and Its Products with Microwave Assisted Sample Digestion

AFS was applied to the determination of As, Sb and Hg in leather and its products. The sample was digested with mixed solution of HNO3-H2O2, and reduced with mixed solution of thiourea and ascorbic acid. Hydrides of the 3 elements were generated from acidic solution using NaBH4 solution (dissolved in NaOH solution) as reducing reagent. Flow-rates of the carrier gas selected were 300 mL·min-1 for As and 400 mL·min-1 for Sb and Hg. Linear relationships between values of fluorescence intensity and mass concentration of the 3 elements were found in definite ranges, with detection limits (3s/k) of 0.22 μg·L-1 (for As), 0.16 μg·L-1 (for Sb) and 0.04 μg·L-1 (for Hg).The proposed method was applied to the analysis of leather and its products, giving values of recovery in the range of 94.0%-107% with RSD′s (n=5) less than 10%.