Abstract: Among common industrial solvents, toluene, mixed xylenes and chloro-benzene have been considered as the most suitable extractants. Data of distribution of l-ephedrine between the above mentioned solvents and pure water (and aqueous sodium hydroxide solution) at different temperatures were obtained. The distribution coefficient, m=(concentration in solvent)/(concentration in aqueous solution), for each solvent is practically constant over the concentration range investigated, increasing with rising temperature from 20 to 60℃. The coefficient is also increased with the addition of sodium hydroxide in the aqueous phase. The relationship between the pll value of the leach liquor and the percentage of alkaloids present in free form was also investigated. It shows that only at pH≥ll.5 practically all alkaloids can be set free and therefore extractable. For the system toluene-leach liquor (with the addition of NaOH to pH=12)-mixed alkaloids present in Ephedra Sinica Stapf, the values of m at 20°,40° and 60° were found to be 2.1, 2.6 and 4.4; and at 60 when chlorobenzene was used m = 5.2. These values of m are smaller than those for the corresponding pure systems. Using mixed xylenes as solvent m at 60° was found to be 5.4, which is somewhat greater than that for the pure system. Alkaloids in the organic solvents can be easily and completely re-extracted into aqueous solution to form hydrochlorides by hydrochloric acid. Thus the solvents can be recovered and returned to the cycle for extraction of leach liquor.

摘要： <正>麻黄是我国驰名世界的特产生药之一,其中所含有效成分,已知有l-麻黄碱、d-ψ-麻黄碱、l-N-甲基麻黄碱、d-N-甲基假麻黄碱、l-去甲基麻黄碱、d-去甲基假麻黄碱及麻黄副素等生物碱。但麻黄中除l-麻黄碱与d-ψ-麻黄碱的含量较多外,其餘各种生物碱的含量却很少,而且目前在医疗上使用的也只是l-麻黄碱,不过d-ψ-麻