【摘要】 本文报道了从苍耳油制备亚油酸的一种尿素-锂盐合并的新方法.采用本法,所得亚油酸,收率特高(40％)质量亦好(98.6％).此外,还可回收一部分油酸.重复试验的结果,证明新法较之常用的方法为佳.更多还原

【Abstract】 A new combined urea-lithium salt method for the preparation of linoleic acid from the seed oil of Xanthium strumarium L. has been developed. The oil was saponified, acidified, and the mixed fatty acids obtained were separated into two parts-saturated and unsaturated-by means of the ordinary alcohol-lead method. The unsaturated fatty acids, consisting mainly of linoleic acid accompanied with a small amount of oleic acid, were treated with lithium hydroxide, and the oleic acid for the most part was filtered off in the form of lithium oleate. To the filtrate, a calculated amount of urea was added, in order to remove the residual amount of oleic acid as its crystalline urea-adducts. By repeating the urea complex procedure, nearly all the oleic acid was removed as above (usually 3 times).The final filtrate consisting of a considerable portion of linoleic acid was then purified by distillation under reduced pressure. By use of this method, the linoleic acid was obtained in excellent yield (40%, on the basis of the total amount of unsaturated fatty acids used) as well as good quality (content: 98.6%, estimated on the basis of iodine number as usual). Besides, a reason- able amount of oleic acid with moderate purity may be recovered. Repeated results indicate that such a new combined method is simple, and more efficient than the conventional ones, including the single urea-adduct method.更多还原