毛细管气相色谱法测定烟草中的甾醇类化合物

Determination of Sterols in Tobacco with Capillary Gas Chromatography

以丙酮为提取剂、1%硫酸的乙醇溶液和2.0 mol/L氢氧化钾的乙醇溶液分别作水解剂和皂化剂、三甲基氯硅烷和六甲基二硅胺烷作衍生化剂,采用毛细管气相色谱法测定了15种烤烟烟叶和10种商品卷烟中的胆甾醇、菜油甾醇、豆甾醇和β-谷甾醇含量.结果表明：①胆甾醇、菜油甾醇、豆甾醇和β-谷甾醇的RSD＜5%,回收率在94.24%～101.22%;②在所测定的烟草样品中,不管是烤烟烟叶,还是烤烟型或混合型卷烟,均是豆甾醇和β-谷甾醇的含量较高,菜油甾醇的含量次之,胆甾醇的含量最低;③同一产地不同部位烟叶样品总甾醇的含量为下部烟＞中部烟＞上部烟;④混合型卷烟的总甾醇含量明显低于烤烟型;⑤同一类型的卷烟,国产卷烟的总甾醇含量较进口的低.

The cholesterol, campesterol, stigmasterol and β - sitosterol in 15 samples of flue-cured tobacco leaves and 10 samples of cigarettes were determined. The samples were extracted with ace- tone, then hydrolyzed in 1% sulfuric acid of ethanol solution, and saponified in 2.0 mol/L potassium hydroxide of alcohol solution, reacted with trimethysilyl chloride and hexamethyldisilazane, and analyzed by capillary gas chromatography. The results showed that： 1 ） the recovery of these sterols ranged from 94.24% to 101.22% with RSD of 〈 5% ; 2） the contents of stigmasterol and sitosterol were the highest in all of the samples, no matter whether it was tobacco leaves or cigarette of Virginia type or blended type; followed by campesterol, and cholesterol was the lowest; 3） the total sterols in tobacco leaves from the same producing area decreased with the elevation of stalk position; 4） the total sterols in Virginia type cigarette was higher than that in blended type one; 5） for the same type cigarette, the total sterols in domestic cigarette was lower than that in imported one.