[Material Composition Research on Tibetan Medicine "Brag-zhun"]

To study the material composition of Tibetan medicine "Brag-zhun", and to provide the basis for interpretation of its source and reference for the establishment of quality standards.

Pharmacognosy routine method was used in macroscopic and microscopic identifications, inductively coupled plasma spectrometry was carried out to determine 26 kinds of mineral elements,and X-ray diffraction analysis was used for the crystalline phase detection of Brag-zhun. The content of calcium,organic matter, humic acid and fulvic acid was determined according to GB/T 14610-2008, "technical specification for soil analysis" , GB/T 11957-2001 and capacity titration, respectively. Moisture, ash content, acid insoluble ash content and water soluble extract were determined with reference to the Chinese Pharmacopoeia (2010 edition).

Animal feces were commonly found in Brag-zhun, the main crystal phase was SiO2, 26 kinds of mineral elements content in total was about 3%, 13 batches of medicinal materials in organic matter content was 29.03%-71.79%. Humic acid content was 28.37%-58.51%; fulvic acid content was 19.69%-41.43%; moisture was 5.2% -11.7%; total ash content was 17.82%-64.39%; acid insoluble ash content was 2.10%-39.09%; and water soluble extract was 28.39%-57.40%.

The traditional record of Brag-zhun from molten juice is lack of scientific basis. The mineral elements in Brag-zhun exist in amorphous. Brag-zhun contains a lot of organic matter including humic acid and fulvic acid, and inorganic matter mainly comes from sediment. The organic matter in rock has gone through a long geological evolution.