| 摘要 |
Substantially pure lecithin is obtained from substances containing the same by extracting the substance with an organic solvent after first removing any water present, adding an inorganic oxidic sol to the extract and decomposing the resulting precipitate by means of acids or alkalies. The pure lecithin is isolated by filtering off the inorganic precipitate and adding acetone or ethyl acetate to the filtrate. In examples: (1) water is removed from fresh egg yoke by treatment with acetone and the lecithin extracted by means of anhydrous ethylalcohol at reduced pressure, and with exclusion of light and oxygen; an alcoholic aluminium oxide sol is added, the resulting precipitate suspended in alcohol, chloroform or carbon tetrachloride and the aluminium precipitated by means of gaseous ammonia; by adding acetone to the inspissated solution the pure lecithin is obtained; (2) crude phosphatide obtained from soya bean oil is dissolved in ether or carbon tetrachloride and treated with alcoholic silica sol; the resulting jelly, after extraction with a little ether is suspended in ether and decomposed with hydrochloric acid; after filtration the lecithin is precipitated by means of acetone; (3) fresh beef's brains, dried by treatment with acetone are extracted with dry methyl alcohol at reduced pressure and an alcoholic iron oxide sol added; the resulting precipitate is suspended in chloroform, treated with ammonia and the separated solution concentrated and treated with acetone. The crude starting material may be dried by means of ethylacetate or with a current of dry air and the oxide sols may be prepared in situ by addition of an alkali, e.g. ammonia or sodium, potassium or lithium hydroxide or carbonate, to an alcoholic solution of the metal salt, e.g. aluminium chloride, sulphate or phosphate. Sols of oxides of zinc, tin, cadmium, copper, chromium, and zirconium are mentioned. Specification 294,264, [Class 1 (i)], is referred to. |
