摘要
采用毛细管气相色谱的方法,以十五碳烷酸为内标,对紫苏子油中的五种游离脂肪酸:棕榈酸(C(16:0))、硬脂酸(C(18:0))、油酸(C(18:1))、亚油酸(C(18:2))、亚麻酸(C(18:3))进行分析,研究紫苏子油中五种游离脂肪酸在储藏期间的变化。此分析方法无需进行甲基化,直接分析游离脂肪酸的变化。研究中对每种脂肪酸都作了方法学研究,脂肪酸的线性范围在 147~922 ppm之内,r~2值≤0.9997。精密度≤2.43%(n=5)。最后用此法测定了不同储藏期间的样品,结果显示随储藏时间的延长,游离脂肪酸的总量增加,但各脂肪酸的变化情况不同。
This paper reports a split-mode capillary gas chromatographic method that developed for the analysis of five free fatty acids in Perilla seed oil. The five free fatty acid are palmitic acid (C_(16:0)), stearic acid (C_(18:0)), oleic acid(C_(18:1)), linoleic acid (C_(18:2))and linolenic acid (C_(18:3)). The method does not need methlated, fatty acids can be directly injected with pentadecanoic acid (C_(15:0)) as internal standard. For each fatty acid, the method is validated for selectivity,linearity, , precision and reptoducibility. All fatty acids are completely resolved. Linear response from 147 to 922ppm, r^2-value at least 0.9997, the precision is not more than 2.62% (within day). Finally, we study on the variation of free fatty acid in perilla seed oil by this method.