气相色谱内标法测定沙棘果肉油和种子油中的主要脂肪酸

Determination of Fatty Acids in Pulp Oil and Seed Oil from Sea Buckthorn by GC Internal Standard Method

以5个沙棘(Hippopha觕rhamnoides L.)品种的果实为试材,建立气相色谱内标法测定沙棘果肉油和种子油主要脂肪酸成分的方法。果肉油和种子油采用氯仿-甲醇法提取,甲醇钠-甲醇法甲酯化衍生后进行定性和定量。结果表明,十九烷酸甲酯是气相色谱法测定沙棘果实中脂肪酸成分含量的理想内标物。果肉油和种子油中的主要脂肪酸为棕榈酸、棕榈油酸、硬脂酸、油酸、亚油酸和α-亚麻酸。果肉油中棕榈油酸(36.25%)和棕榈油酸(28.92%)含量高,α-亚麻酸含量低;种子油中亚油酸(33.65%)和α-亚麻酸(32.95%)含量高,棕榈油酸含量低。5个品种沙棘的果肉油和种子油中主要脂肪酸的组成及含量存在一定的差异。亚历山大12号果肉油中的脂肪酸含量最高,为84.84 g/100 g油;无刺丰种子油中的脂肪酸含量最高,为88.39 g/100 g油。该方法操作简便、快速、重复性好,适合沙棘油脂样品中脂肪酸的定量测定。

A gas chromatographic method for determination of fatty acids in pulp oil and see d oil was established with five cultivars of sea buckthorn berries as materials. The pulp oil and seed oil were extracted using chloroform-methanol method. The qualitative and quantitative analysis of fatty acids in oils were performed after they were methylated with CH3ONa-CH3OH. The results showed that methyl nonadecylate was optimal internal standard to analyse the contents of fatty acids in pulp oil and seed oil from sea buckthorn. The main fatty acids included palmitic,palmitoleic,stearic,oleic,linoleic and a-linolenic acids. In pulp oil,the contents of palmitoleic acid （36.25%） and palmitic acid （28.92%） were high and a-linolenic acid was few. In seed oil, the contents of linoleic acid （33.65%） and a-linolenic acid （32.95%） were high and palmitoleic acid was few. There were some differences in composition and content of main fatty acids among five cultivars. The pulp oil from Yalishanda-12 exhibited the highest content of total fatty acids at 84.84 g/100 g oil,respectively. The seed oil from Wu-cifeng contained highest total fatty acids at 88.39 g/100 g oil. The method is simple,effective and accurate for the fatty acid determination of sea buckthorn oil samples.