分光測色計を用いた生薬滑石の識別に関する研究

抄録

“Kasseki” is defined as “a mineral substance, mainly composed of aluminum silicate hydrate and silicon dioxide. It is not the same substance as the mineralogical talc” in The Japanese Pharmacopoeia (JP), while, “Huashi” is defined as “mainly hydrated magnesium silicate” in Pharmacopoeia of The People’s Republic of China (CP). Thus, the origins of Kasseki defined in JP (JP Kasseki) and Huashi defined in CP (CP Huashi) are different from each other even though they are highly similar as to morphological characteristics. The Kasseki distributed in the market and used in Japan is almost all imported from China. Previously, we have found that Japanese and Chinese markets have at least six (one is in Japan and five are in China) types of these mineral crude drugs (Types A-F) by using an X-ray diffraction method. These facts suggest that mineral crude drugs other than JP Kasseki may be mistakenly imported as Kasseki from the Chinese market to Japan in the future in response to increased demand. In this paper, for development a new simple and easy method for discrimination of the six types of this mineral crude drug, we investigated their color by using a spectrophotometer for L*, a*, b* values as defined by the CIE 1976 L*a*b* Color system. Among the six types, it was difficult to distinguish them from each other because we observed only slight differences in value among them, thouh the values of some parameters differed widely. On the other hand, the result suggested that it would be possible to discriminate Type A (JP Kasseki) from Type D (CP Huashi) by using this method. Furthermore, we examined ten samples of Type A and Type D, and significant differences were recognized for each L*, a* and b* value. These data suggested that the method using a spectrophotometer is valid for the discrimination JP Kasseki from CP Huashi.