常规湿化学分析方法测定中药中无机元素, 需要先将样品消解, 再经滴定或者仪器测定, 操作繁琐、 费时。 对于含朱砂或雄黄的制剂, 由于汞、 砷含量很高, 会对实验器皿和仪器造成污染。 X射线荧光光谱(XRFS)具有操作简便、 分析速度快、 多元素同时检测、 可实现无损分析等优点。 以电感耦合等离子体发射光谱法(ICP-OES)为参比, 应用便携式XRFS建立了牛黄清心丸(局方)中汞、 砷含量的快速无损测定新方法, 并首次将X射线荧光光谱技术用于药品的均匀性评价。 优化了测量模式, 以电感耦合等离子体发射光谱法测定值为参比, 建立校正工作曲线用于样品测定。 实验表明, 便携式X射线荧光光谱法测定Hg和As, 精密度高, 相对标准偏差(RSD)分别为0.09%和0.23%。 测定值与参比值接近, Hg和As的相对平均偏差分别为8.58%和5.95%, 符合现场快检的要求。 结果显示, 2批次样品Hg含量异常低, 1批次样品As含量异常高, 1个厂家的样品均匀度差。 所建方法快速、 简便、 经济、 环保, 为含矿物中药的质量控制提供了新的思路。 便携式仪器的使用, 能高效完成大批量样品的分析, 及时发现药品的质量隐患, 节约时间、 人力和物力, 具有良好的应用前景。

Determination of inorganic elements in traditional Chinese medicine by conventional wet-chemistry approach is complex and time-consuming. The samples must be digested before instrumental analysis. For preparations containing cinnabaris or realgar, high content of Hg and As will contaminate lab wares and instruments. However, X-ray fluorescence spectrometry is simple, fast and can simultaneously determine multiple elements in a non-destructive way. In this paper, portable X-ray fluorescence spectrometry was applied to establish a novel method for rapid and nondestructive determination of Hg and As in Niuhuang Qingxin Pills. And the method was employed in homogeneity analysis of the drug for the first time. After optimization of the measurement mode, using the inductively coupled plasma-optical emission spectroscopy as the reference value, working calibration curve was obtained for determination. Experiments results showed that precision was high with relative standard deviation of 0.09% and 0.23%, respectively, and the determination results of Hg and As were close to the reference values with relative mean deviations of 8.58% and 5.95%, respectively, which met the requirements of on-site rapid screening. Results indicated that contents of Hg in 2 batches of the samples were abnormally low and contents of As in 1 batches of the samples was abnormally high. Sample from 1 manufacturer was inhomogeneous. The proposed method was quick, simple, economic and environment-friendly, which offered a new approach for quality control of traditional Chinese medicine containing mineral. The portable instrument brings high efficiency and high throughput, which can help revealing hidden danger of drug quality. In all, X-ray fluorescence spectrometry can save time, manpower and resources, and has a bright prospect in application.