紫石英的X射线衍射与拉曼光谱鉴别

Identification of Fluoritum by X-ray Diffraction and Raman Spectrum

目的：分析紫石英的X射线衍射（XRD）图谱和拉曼光谱指纹特征,为该药材的快速有效鉴别提供参考。方法：紫石英样品及其混淆品方解石、白石英进行X射线衍射分析,确定各样品的物相组成和主成分Ca F2的含量,入射光源Cu靶Kα射线,Ni片滤波,X管工作电压40 k V,电流40 m A,光阑系统发散狭缝和防散射狭缝均为1度,接收狭缝0.3 mm。在此基础上,分析各样品在61~2 695 cm-1的拉曼光谱特征。扫描参数为激发光源785 nm,光谱测量61~2 695 cm-1,激光功率300 m V,1.5 m光纤探头,激光强度100%。结果：XRD分析表明1~15号样品为正品紫石英,16~20号为掺伪品,21号为伪品。正品紫石英拉曼光谱在310~325,720~1 500,1 700~1 900 cm-1处有3组拉曼指纹特征峰,据此能很好地鉴别紫石英的真伪。结论：XRD图谱可准确分析紫石英的物相组成,为紫石英的拉曼光谱鉴定方法提供准确的原始样品数据。拉曼光谱鉴别紫石英具有很好的专属性,可作为一种快检方法准确、快速地区分紫石英及其混伪品。

Objective： To analyze X-ray diffraction （XRD） and Raman spectrum fingerprint characteristics of Fluoritum, and to provide a reference for its fast and effective identification. Method： XRD was used to determine phase composition and the content of CaF2 from Fluoritum, Calcite and Quartz with Cu target Kα radiation as incident light source, filter of Ni, 40 kV as X-ray tube voltage, 40 mA as the current, 1 degree as divergence slit （SD） and scattering slit （SS）, 0.3 mm as receiving slit. On this basis, Raman spectrum characteristics of Fluoritum in the range of 61-2 695 cm-1, with 785 nm as wavelength of excitation light source, 300 mV as laser power, 1.5 m optical fiber probe and laser intensity of 100%. Result： Analysis of XRD indicated that samples 1-15 were Fluoritum, samples 16-20 were adulterants and sample 21 was counterfeiter. Fluoritum had 3 groups of characteristic peaks of Raman spectrum in the range of 310-325, 720-1 500, 1 700- 1 900 cm-1,which can be used to identify its authenticity. Conclusion： XRD can accurately determine phase composition of Fluoritum, which provides original sample data to identify Fluoritum by Raman spectrum. As a way of fast analysis technology, Raman spectroscopy has good specialization, it can identify Fluoritum and its adulterants, counterfeiters.