湖光牛奶脂肪酸的气相色谱-质谱联用分析

ANALYSIS OF FATTY ACIDS IN HUGUANG MILK BY GAS CHROMATOGRAPHY AND MASS SELECT-DETECTOR

[目的]建立简易方法检测湛江市湖光牛奶脂肪酸,并分析其营养价值。[方法]以BF3/MeOH溶液为衍生化试剂,正十七碳饱和脂肪酸(C17:0)为内标,牛奶脂肪酸的抽提和甲酯化一步完成;经DB-WAX石英毛细管柱分离,气相色谱-质谱联用仪(GC-MS)进行定性定量分析。[结果](1)本方法重现性试验脂肪酸CV为1.15%～5.68%,仪器重现性CV为2.31%～9.81%,回收率为84.2%～105.0%。(2)湖光牛奶含有16种脂肪酸,平均饱和脂肪酸:单不饱和脂肪酸:多不饱和脂肪酸为11.80:4.38:1,饱和脂肪酸的含量最高,达到69%;多不饱和脂肪酸的含量最低,仅为6%;ω-6/ω-3脂肪酸比率为2.30。[结论]本方法高效易行,准确可靠,节省时间,适合大标本量的检测;湖光牛奶饱和脂肪酸,单不饱和脂肪酸和多不饱和脂肪酸比例不均衡,有必要优化脂肪酸的组分以提高其营养价值。

[Objective]To develop a simplified method for determination of fatty acid and evaluate the nutrition value of HuGuang fresh milk in Zhanjiang.[Methods]BF3/MeOH solution as derivatization reagent,C17：0 as internal standard,the fatty acid was extracted and methyl esterified in one step,isolated by DB-WAX silica capillary column,identified and determined by gas chromatograph equipped with mass spectrometer.[Results]（1）Reproducibility test of fatty acid（CV）in the milk sample was1.15%-5.68%,equipment reproducibility（CV）was 2.31%-9.81%,and the recovery rate was 84.2%-105.0%.（2）16 kinds of fatty acid could be determined by GC-MS which from HuGuang milk.The ratio of average SFA：MUFA：PUFA was 11.80：4.38：1.The content of saturated fatty acids was the highest（about 69%）;the content of polyunsaturated fatty acids was the lowest（only 6%）.The ratio of ω-6/ω-3 PUFA was about 2.30.[Conclusion]The method is simple,accurate and reliable,which costs less time,and is of high performance.It＇s suitable for the detection of large specimen.The ratio of fatty acid composition of Huguang milk is disproportion.It is necessary to optimize the proportion of fatty acid in milk to improve the nutrition value.