FAAS Determination of Trace Amounts of Lead and Cadmium in Feed Additive with Solvent Extraction

Feed additive sample was digested by hydrochloric acid. 80 g·L^-1 DDTC-Na solution was used as complexing agent and 50 g·L^-1 KCN solution was used as masking agent. After CCl₄ extraction, trace amounts of lead and cadmium in organic phase were determined by FAAS with light source of xenon lamp. Linear relationships between values of absorbance and mass fraction of lead and cadmium were kept in definite ranges, with detection limits (3s) of 100, 50 μg·kg^-1 respectively. The proposed method was applied to the analysis of the sample of feed additive, giving values of recovery and RSD's (n=6) in the ranges of 93.0%-96.0% and 1.6%-3.8% respectively.