脂肪酸的提取.doc

提取方法主要有BlighDyer法及Folch法。前者适用于大量脂类的提取，提取率在95甚至更高；后者适用于少量组织内脂的提取，提取率在9599。我们在实验中常用Folch法。称取1 g待测样品，加入10 ml甲醇，加少量酸洗砂研磨，匀浆1 min，然后加入20 ml氯仿，继续匀浆2 min，过滤，滤渣中加入氯仿一甲醇混合液(2：1 VV)30 ml并研磨，过滤。先用20 ml氯仿及10 ml甲醇洗涤滤渣，合并滤液，然后加入全部滤液体积14的水，振荡，静置分层，将上层及界面处固体物吸除去，然后加入甲醇一水混合物(1：1)，体积为下层体积的14，振荡，静置分层，吸掉上层液体及界面物，重复洗涤两次。然后将有机相减压蒸干，配制成氯仿溶液，一20下保存。注意：在分析植物组织中的脂质时，需要用加热法使植物中的脂酶失活。1皂化、酯化 取约4 mg的总脂按CarreauDubacq法，加入约1 ml 15的NaOHMeOH(或1NaMeOH)溶液，在55。C水浴中加热30 min，然后加入15 ml HClMeOH，水浴加热30 min，加05 ml左右的蒸馏水，然后用4 mlEg烷萃取，吸取正己烷层，重复两次。然后将萃取液减压蒸干，加入03 ml氯仿。Modified Folch procedureHomogenised tissue (10 g) was progressively added tosmall amounts of a chloroform/methanol 2:1 (v/v) mixture(up to 200 ml), with vigorous shaking, and then theextraction was carried on for a further 2h, using anelectromagnetic stirrer. The mixture was filtered and thefilter was re-washed with fresh solvent and pressed.Fifty millilitres of 0.88% potassium chloride were addedand the mixture was shaken. The aqueous layer (upper)was removed by aspiration and the washing procedurewas repeated. The extract was then dried by addinganhydrous sodium sulphate, which was filtered again,before the solvent was removed using a rotary evaporator.The extract was then placed in a desiccatorovernight and weighedExtraction by acid hydrolysisHomogenised tissue (10 g) was progressively added tosmall amounts of a chloroform/methanol 2:1 (v/v) mixture(up to 200 ml), with vigorous shaking, and then theextraction was carried on for a further 2h, using anelectromagnetic stirrer. The mixture was filtered and thefilter was re-washed with fresh solvent and pressed.Fifty millilitres of 0.88% potassium chloride were addedand the mixture was shaken. The aqueous layer (upper)was removed by aspiration and the washing procedurewas repeated. The extract was then dried by addinganhydrous sodium sulphate, which was filtered again,before the solvent was removed using a