Electrochemical hydride generation atomic fluorescence spectrometry for the simultaneous determination of arsenic and antimony in Chinese medicine samples

A new method for the simultaneous determination of As and Sb by using AFS coupled with a newly designed electrochemical hydride generator has been developed. The hydride generator is a tubular electrolytic cell of 28 mm i.d. and 45 mm length, which consists of a graphite tube cathode and a platinum anode. Gaseous hydrides of As and Sb are generated at the cathode. Through a gas-liquid separator, the hydrides are directly transported to the atomizer by an Ar flow for determination. A detection limit of 0.50 and 0.30 μg l−1 (3σ) for As and Sb in synthetic samples containing10 mg l−1 Cu, Ni and Co was obtained, respectively. The precision (n = 11) for 50 μg l−1 As and Sb was 2.1 and 1.5%, respectively. The method was successfully applied for determination of total As and Sb in Chinese medicine samples.