Closed-vessel microwave-assisted digestion was utilized for the decomposition of hard-to-dissolve optical glass samples for the determination of the ultra trace amount of cadmium by electrothermal evaporation atomic fluorescence spectrometry（ETV-AFS）and arsenic and lead by hydride generation atomic fluorescence spectrometry（HG-AFS）.The limits of detection were found to be 0.08,0.1 and 0.7ngmL-1for cadmium,arsenic and lead,respectively.Relative standard deviation（RSD）was between 2%-5% which was adequate for trace analysis.The analytical results were in good agreement with those obtained by inductively coupled plasma mass spectroscopy（ICP-MS）for cadmium and inductively coupled plasma atomic emission spectrometry（ICP-AES）for arsenic and lead.
A method was proposed to determine As,Pb,Cd,and Hg in ten kinds of Chinese medicinal herbs by ICP-MS.The proposed method was quick,efficient and accurate.
The contents of As,Cd,Hg and Pb in 27 Chinese medicinal herbs were determined by ICP-MS with microwave assisted digestion.Cluster analysis was applied to study the distribution characteristics of As,Cd,Hg and Pb in different kinds of Chinese medical herbs from different sources.The result of cluster analysis showed that the contents of As,Cd,Hg and Pb from different sources were significantly different.It is helpful in the quality control and source identification of Chinese medicinal herbs.
