Non α- tocopherol in mixed tocopherols concentrate were transformed into α - tocopherol by aminomethylation - reduction, then high purity α - tocopherol was separated by column chromatography with 100 -200 meshes silica gel as stationary phase and dichloromethane - ethyl acetate as eluent The effects of solvent, reaction temperature and time on aminomethylation, and volume ratio of eluent,flow rate and sample loading amount on separation efficiency were investigated. The optimal conditions were as follows:cyclohexane as solvent, reaction temperature 80℃, reaction time 2.5 h, volume ratio of dichloromethane to ethyl acetate 98:2,flow rate 1.5 mL/min,sample loading amount 7. 5 mL(mass concentration 0.1 g/mL). The content of α - tocopherol in mixed tocopherols concentrate improved from 4. 61% to 90.77% ,and the recovery rate was 78. 85% by the combination of the two methods. The structure of the product was consistent with α - tocopherol standard by characterization methods of FTIR and HPLC/ APCI-MS.%采用胺甲基化-还原法将混合生育酚浓缩液中的非α-生育酚转型为α-生育酚；采用柱层析法,以100 ～200目硅胶为固定相、二氯甲烷-乙酸乙酯为洗脱剂,将转型后的α-生育酚粗品经分离纯化得到高纯度α-生育酚.实验分别考察了溶剂、反应温度和反应时间对胺甲基化反应的影响以及洗脱剂体积比、流速和进样量对柱层析分离效果的影响.确定了最佳条件为:胺甲基化反应,环己烷作溶剂,反应温度80℃,反应时间2.5h；柱层析洗脱剂二氯甲烷-乙酸乙酯体积比98:2,流速1.5 mL/min,进样量7.5 mL(质量浓度0.1 g/mL).通过两种方法可将混合生育酚浓缩液中α-生育酚纯度由4.61％提高到90.77％,回收率为78.85％；经全反射傅里叶红外光谱(FTIR)、大气压化学电离源液质联用(HPLC/APCI-MS)表征证明产品结构与α-生育酚标准品基本吻合.
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