亚麻籽甘油二酯油中甘油二酯异构体的 气相色谱-质谱联用表征Characterization of diacylglycerol isomers in flaxseed diacylglycerol oil using GC-MS

旨在为植物油中甘油二酯的检测与分析提供技术参考，以亚麻籽甘油二酯油为检测样品，经两级固相萃取纯化后采用气相色谱-质谱联用法（GC-MS）对亚麻籽甘油二酯油中的甘油二酯进行分析，根据甘油二酯的特征离子碎片分析甘油二酯的组成，通过总离子流色谱（TIC）图及提取离子色谱（EIC）图对异构体进行研究，并与高效液相色谱法（HPLC）进行对比。结果表明：亚麻籽甘油二酯油经两次固相萃取后可以得到纯度较高的甘油二酯，Rxi-65TG气相色谱柱的分离效果优于DB-5ms的；特征离子碎片分析结果和EIC表明亚麻籽甘油二酯油中共含有20种甘油二酯，主要为1-亚油酸-3-亚麻酸甘油二酯（21.36%）、1，3-二亚麻酸甘油二酯（16.57%）和1-油酸-3-亚麻酸甘油二酯（15.75%）；相较于HPLC，GC-MS可以实现甘油二酯的准确定性与定量，且峰分离度优于HPLC。综上，GC-MS可用于植物油中甘油二酯的组成分析。Aiming to provide technical reference for the detection and analysis of diacylglycerol in vegetable oils, the diacylglycerol in flaxseed diacylglycerol oil was analysed by gas chromatography-mass spectrometry (GC-MS) after purification by two stage solid phase extraction using flaxseed diacylglycerol oil as the test sample, the composition of the diacylglycerol was analysed based on the characteristic ionic fragments of the diacylglycerol, the composition of the diacylglycerol was analysed through the total ion current chromatogram (TIC) and the extracted ion chromatogram (EIC) for the study of isomers and compared with the high performance liquid chromatography (HPLC) method for the determination of diacylglycerol. The results showed that high purity diacylglycerol could be obtained after two stage solid phase extraction of the flaxseed diacylglycerol oil, and the separation effect of the Rxi-65TG GC column was better than that of the DB-5ms. The results of the characteristic ionic fragmentation analysis and the EIC indicated that the flaxseed diacylglycerol oil contained a total of 20 kinds of diacylglycerols, which mainly consisted of 1-linoleic-3-linolenic acid diacylglycerol(21.36%), 1, 3-di-linolenic acid diacylglycerol(16.57%) and 1-oleic acid-3-linolenic acid diacylglycerol (15.75%). Compared with HPLC, GC-MS could achieve accurate characterization and quantification of diacylglycerol, and the peak separation was better than that of HPLC. In conclusion, GC-MS can be used for the analysis of the composition of diacylglycerol in vegetable oils.