1970 年 90 巻 8 号 p. 1039-1047
The six principal alkaloids of opium can be separated into three groups by sequential extractions with solvents as follows : the first group (noscapine, papaverine and thebaine) comes in chloroform, the second group (codeine and thebaine) in benzene, while the third group (morphine and narceine) remains in the aqueous phase. These separations are easy and almost quantitative, except that thebaine comes in the two extracts, but further separations to one component in one solution, are complicated and hardly expected to be quantitative. Moreover, the wavelengths at the maximum ultraviolet (UV) absorption of these alkaloids lie closely with one another and these facts make the spectrophotometric determination of the individual component difficult. These facts, expecially the proximities of the wavelengths at the maximum UV absorption of components concerned, however, are assumed to be suitable or essential to the application of Y-reference method, which has been reported by Alien and coworker as a spectrophotometric determination of one component in a two-component mixture. In the present report, three kinds of artificially prepared standard solutions of alkaloids, corresponding to the above mentioned three groups, were analysed by Alien's method, being somewhat modified. As a solution for spectrophotometric measurement, about a 10mg/100ml to 20mg/100ml in 0.1N hydrochloric acid solution for each alkaloid -group was used ; the results showed that the coefficient of variation of the analytical data and the mean value of the recoveries, obtained by 10 determinations with respect to each alkaloid, were; codeine : 1.49, 102.4% ; thebaine : 2.27, 98.3% ; morphine : 1.61, 99.3% ; narceine : 1.36, 99.0% ; noscapine : 0.81, 99.0% ; papaverine : 2.34, 100.3%; thebaine (from three-component solution) : 1.29, 100.8%.