Determination And Comparative Study Of Trace Elements In Traditional Chinese Medicine Before And After Processing

Chinese traditional medicine is treasure of Chinese traditional physic. The study of trace elements contained in Chinese traditional medicine is an important part of the Chinese traditional medicine research. A method was established for the determination of Mg, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sn, Ba, Hg and Pb in Radix et rhizoma rhei, radix astragali, radix scutellariae, radix polygoni multiflori and radix rehmanniae by microwave digestion-ICP-MS. The contents and primary speciations of 18 trace elements contained in the five Chinese traditional medicines, their processed products and their respective decoctions were studied. Tentative discussion about the relationship between trace elements and processing, drug properties was made.A method was established for the determination of 18 elements in five Chinese traditional medicines, processed products and their respective decoctions by microwave digestion-ICP-MS. The suitable sample preparation had been developed. The microwave digestion condition was optimized from digestion system, proportion of acids and digestion procedure, which affords reference for the preparation of root and rootstalk herds. Parameters of ICP-MS were optimized. Detection limits of all elements were lower than 1 μg/L, precisions were between 2.39% and 8.90%, recoveries were between 70%-130%. The accuracy was verified by tea standerd reference material. The analytical results of tea SRM were within the certificated values. The result showed that the contents of elements changed before and after processing, implying the procedure of processing had some impact on the contents of elements.Primary speciation of 18 trace elements (Mg, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sn, Ba, Hg and Pb) was studied. The samples of primary speciation were obtained from primary analytical flow, and the contents of 18 trace elements were determined by ICP-MS. The parameters of species distribution, such as extractive rate, residual rate, immerse-residue ratio etc were also caculated. The elements oder of decoction from difficult to easy in different Chinese traditional medicines was different. It was also differential after and before processing. Each herb had its' characteristic elements easy to be decocted, indicated that these elements had the greater function. In these herbs, the residual rates of Al, V, Cr, Fe were biger than other elements, the extractive rates of Zn, Mg, Mn were biger than other elements. It showed some relationship to their speciations. More datum and usefull information were gained than gross of elements, because the analysis of primary speciation was gained by traditional decoction. In comparison of contents and extractive rates of trace elements after and before processing, we found that the content diversities caused by processing of radix astragali, radix scutellariae, radix polygoni multiflori and radix rehmanniae were coincident to the relationship between contents and drug properties which had been reported. After processing, the contents of elements in warm (hot) drugs degraded, and the contents of elements in cool (cold) drugs ascensused. The content diversities of radix et rhizoma rhei caused by processing were not coincident to the report. Advanced research was required. Not only the contents but the extractive rates changed. It showed that processing made the speciation of some trace elements change, resulting some elements easy to be decocted or difficult to be decocted.The contents and extractive rates of Mg, Mn, Fe, Zn in radix astragali, radix polygoni multiflori, radix rehmanniae were bigger after processing, it was considered that these herbs had the tonification, and implied the restorative characties of Mg, Mn, Fe, Zn and their organic principles cooperate with each other.