[Determination and risk assessment of heavy metals and harmful elements residues in Niuhuang Qingwei Pills based on ICP-MS].

To achieve a comprehensive understanding of heavy metals and harmful elements residues in Niuhuang Qingwei Pills,49 samples from 18 manufactures were collected from 31 provinces in China.Risk assessment and control preparations were applied innovatively in evaluation of exogenous pollution in traditional Chinese Medicine.Determination methods for Pb,Cd,As,Hg and Cu were established by inductively coupled plasma mass spectrometry(ICP-MS).Based on the procedures including hazard identification,hazard characterization,exposure assessment and risk characterization,risk assessment was performed and residual limits for Pb,Cd,As,Hg and Cu in the drug were formulated.The results showed that the hazardous quotients(HQ) of the elements were decreased in the following order:Pb>As>Cu>Hg>Cd,and the total hazardous index(HI) of heavy metals and harmful elements in Niuhuang Qingwei Pills was above 1,implying health risk of the drug.Under the proposed limits,5 elements in the control preparation as well as Cd and Cu in the samples were within the limits range,but the excess rates of Pb,As and Hg in the samples were 12%,12% and 14%,respectively.For the first time,basic steps for risk assessment of Chinese patent medicine were established,which provided model and reference for risk assessment and limit formulation of other drugs.