[Speciation analysis of mercury in traditional Chinese medicine by vapor-generation atomic fluorescence spectrometry].

A sensitive method has been proposed for the determination of inorganic mercury and total organic mercury in traditional Chinese medicine (Wanshi Niuhuang Qingxin) by vapor-generation atomic fluorescence spectrometry. The experimental conditions that influence the atomic fluorescence signal intensity of Hg and the oxidization of organic mercury were investigated and optimized. Thiourea citric acid was selected as a sensitization agent, which greatly enhanced atomic fluorescence signal intensity of mercury. The influence of foreign ions and their elimination were studied. The detection limit of the method for Hg was 7.6 ng x L(-1) and the relative standard deviation was 1.56%-3.28% for Hg. The proposed method was successfully applied to the determination of mercury speciation in real samples with a recovery range of 90.3%-110.3%.