不饱和脂肪酸的气相色谱法同时测定

Determination of the contents of unsaturated fatty acid by GC in the meantime

目的:建立不饱和脂肪酸含量的测定方法.方法:采用衍生气相色谱程序升温同时测定4个成分.结果:平均回收率为 95%～105%,RSD为 0.39%～2.81%.结论:该方法可以用于保健品及食品中不饱和脂肪酸的测定.

Objective:To establish a method for the simultaneous determination of Linoleic acid(LA),Linolenic acid(GLA),Eicosapentaenoic acid(EPA) and Docosahexaenoic acid(DHA) in healthy food by capillary gas chromatography(APGC).Methods:LA,GLA,EPA and DHA were extracted by hexane.The extracted acid were esterified to form methyl ester by H 2SO 4-CH 3OH(1∶9).The effect of methyl ester such as amount,temperature,time have been settled.The effect of operating condition of gas chromatography such as the temperature of column,flow rate,split rate on the response and separation of LA,GLA,EPA and DHA was investigated and acquired optimum operating condition.In this optimum operating condition ,the concentration of LA,GLA,EPA and DHA in healthy food was analyzed and tested.Results:The relative standard deviation was less than 3%;the recovery rate ranged from 95.0% to 104.8%;the detection limit was 6.50× 10 -6 μg ,1.32× 10 -5 μg ,2.68× 10 -6 μg ,1.18× 10 -5 μg ,respectively.Conclusion: In a word,the proposed method is rapid and suitable for the determination of LA,GLA,EPA and DHA.