GC-MS法用于食用油中EPA、DHA酯化反应的评估及含量测定

Evaluation and determination of EPA and DHA esterification in edible oil by GC-MS

摘要：采用三氟化硼一氢氧化钠一甲醇回流法酯化食用油中的二十碳五烯酸（EPA）和二十二碳六烯酸（DHA），对该酯化反应过程进行了酯化率的评估，并结合气相色谱-质谱建立了一种用于测定食用油中EPA和DHA的定性、定量分析方法。结果表明：该方法有效可行，在一定的质量浓度范围内，EPA和DHA酯化率高达95％以上；建立的线性方程在20～1200mg／L范围内相关系数大于0．999，产品的加标回收率在90％～110％之间，相对标准偏差在3．72％-7．09％之间。该方法稳定、准确、可行，线性定量范围宽，适合于多种食用油中EPA和DHA的定性、定量分析。

EPA and DHA in edible oil were esterified by boron trifluoride -NaOH -methanol reflux method, and the esterification rate of the esterified process was evaluated, meanwhile an qualitative and quantita- tive analytical method was established for determining EPA and DHA in edible oil by GC - MS. The re- suits showed that the method was feasibility; the esterifieation rates of EPA and DHA could reached over 95% in a certain mass concentration range, and the correlation coefficients of the linear equations were more than 0. 999 in 20 - 1 200 rag/L, the recovery of standard addition were 90% - 110% and the rela- tive standard deviations were 3.72% - 7.09%. The method was stable, accurate, feasible and had a wide- linear quantitation range, it could be used for qualitative and quantitative analysis of EPA and DHA in various edible oils.