Principle of Tibetan medicine fluoritum processing by vinegar based on the change of microstructure and chemical composition

Traditional Chinese medicine (TCM) processing is a cultural treasure of the Chinese nation. The vinegar-quenched processing method of mineral medicine is an important part of traditional Chinese medicine theory. Fluoritum is a commonly used clinical drug in Chinese medicine. Its microstructure and chemical composition will change after vinegar quenching, which will reduce its toxicity and enhance its efficacy. However, the study of chemical composition changes during vinegar quenching is insufficient. The purpose of our study is to compare the chemical composition in differences of fluoritum vinegar processed products from the aspects of microstructure, content of main and trace elements, content of organic elements. The microstructure, content of carbon and nitrogen elements, main and trace elements of fluoritum were observed by thermal field emission scanning, energy spectrum, organic element analyzer, X-ray fluorescence spectrometer and inductively coupled plasma mass spectrometer. The results showed that the particles of vinegar quenched water flying fluoritum processing product became more finer and uniform than other processing product (RSD = 18.9%). The contents of carbon and nitrogen in the vinegar quenched water flying fluoritum processing products are 0.185% and 0.028%, and their contents are increased by nearly 4 and 5 times than fluoritum raw product, respectively. There was no significant change in CaF₂ content in different fluoritum processing products (RSD = 1.61%), but the iron content has nearly doubled. The trace elements in fluoritum show that the contents of different trace elements in fluoritum are very different (RSD = 230%). The elements whose content increased significantly after the vinegar quenched water flying were Li, V, Zn, Ga, Cr (RSD = 80%,RSD = 84.2%,Zn content has never been detected to 11.3 μg.g^-1, RSD = 62.3%, RSD = 51.3%). The elements content with decreased are Tl, W (RSD = 25.4%, RSD = 79.5%). The vinegar quenched water flying processing method can be listed as the best processing method for fluoritum because it can make the fluoritum particles smaller and more uniform, increase the content of organic matter and remove toxic and harmful metal elements. The decrease of grain size, the increase of contents of carbon, nitrogen and iron and the decrease of toxic elements Tl, W and U may be the important reasons for the enhancement of efficiency and reduction of toxicity of fluoritum vinegar-quenched processing.