气相色谱法同时检测南极磷虾中2种ω-3脂肪酸含量

Simultaneous determination of 2 kinds of ω-3 fatty acids in Euphausia superba by gas chromatography

目的建立甲酯化-气相色谱法同时检测南极磷虾中二十碳五烯酸(eicosapentaenoic acid,EPA)和二十二碳六烯酸(docosahexaenoic acid,DHA)含量的分析方法。方法样品经二氯甲烷提取后,与0.5%硫酸-甲醇溶液在60℃条件下反应30 min,反应液使用硅酸镁柱层析净化。将洗脱液转移至15 mL离心管中,2000 r/min离心20 min,上清液氮吹浓缩后,用乙腈定容至1 mL,使用DB-1701色谱柱(30 m×0.32 mm,1.00μm)分离,火焰离子化检测器检测,外标法定量。结果方法在0.02~2.00 mg/mL的线性范围内,相关系数为0.9999。平行样品的相对标准偏差不超过6%(n=3),平均回收率大于82.6%。结论该方法简便高效、检出限低、重现性好,可用于新鲜和干燥南极磷虾样品中EPA和DHA的检测。

Objective To establish an analytical method for the simultaneous determination of eicosapentaenoic acid(EPA)and docosahexaenoic acid(DHA)in Euphausia superba by methyl esterification-gas chromatography.Methods The samples were extracted with dichloromethane,and reacted with 0.5% sulfuric acid-methanol solution at 60℃ for 30 min,the reaction solution was purified by magnesium silicate column chromatography.Subsequently,the eluate was transferred to a 15 mL centrifuge tube,and centrifuged at 2000 r/min for 20 min,the upper solution was concentrated by blowing nitrogen,and the solution was diluted with acetonitrile to a final volume of 1 mL,then,the obtained sample was separated using a DB-1701 chromatographic column(30 m×0.32 mm,1.00μm),and then detected by a flame ionization detector,and quantified by an external standard method.Results The method had good linear correlations within the concentration range of 0.02-2.00 mg/mL with correlation coefficients were 0.9999.The relative standard deviations of parallel samples were no more than 6%(n=3),and the average recoveries were greater than 82.6%.Conclusion This method is simple and efficient,with low detection limit and good reproducibility,it can be suitable for the determination of EPA and DHA in fresh and freeze-dried Euphausia superb samples.