同位素内标-气相色谱-质谱法测定食用植物油中缩水甘油酯

Determination of glycidyl esters in edible vegetable oil by isotopic internal standard-gas chromatography-mass spectrometry

建立了一种同位素内标-气相色谱-质谱法测定食用植物油中缩水甘油酯(GEs)的检测方法。先将GEs转化成3-溴-1,2-丙二醇(3-MBPD)单酯,再通过水解、衍生化,然后气相色谱-质谱法测定3-溴-1,2-丙二醇(3-MBPD)含量,并对衍生条件进行优化。结果表明:优化的衍生条件为GEs质量浓度为21.78μg/mL时,苯硼酸(PBA)用量100μL,衍生温度50℃,衍生时间10 min。该方法在GEs质量浓度为0.0218~2.178μg/mL范围内线性关系良好(R=0.9999),检出限为25μg/kg,平均加标回收率为91.4%~97.0%,相对标准偏差为4.4%~8.6%。该方法的可操作性强、重现性好,灵敏度、准确度和精密度均能满足实际工作中食用植物油中GEs的定性定量检测。

An isotopic internal standard-gas chromatography-mass spectrometry method was established for the determination of glycidyl esters(GEs)in edible vegetable oil.GEs were converted to 3-monobromopropanediol(3-MBPD)monoesters,and then the 3-MBPD content was determined by gas chromatography-mass spectrometry(GC-MS)after hydrolysis and derivatization.The conditions of derivatization were optimized.The results showed that the optimal derivatization conditions were obtained as follows:mass concentration of GEs 21.78μg/mL,phenylboronic acid(PBA)dosage 100μL,derivatization temperature 50℃,derivatization time 10 min.Good linearity was obtained(R=0.9999)with the mass concentration of GEs in the range of 0.0218-2.178μg/mL.The limit of detection of GEs was 25μg/kg,and the mean recovery rate of standard addition was 91.4%-97.0%with a relative standard deviation of 4.4%-8.6%.The method was applicable and reproducible with good sensitivity,accuracy and precision,which could be used for qualitative and quantitative determination of GEs in edible vegetable oil in actual work.