超高效合相色谱-质谱法测定大豆油中5种脂肪酸含量

建立了大豆油中5种脂肪酸的超高效合相色谱-质谱(UPC-MS)分析方法,这5种脂肪酸分别为棕榈酸、硬脂酸、油酸、亚油酸和亚麻酸.待测物经皂化反应后,用正己烷溶解,经ACQUITY UPC BEH 2-EP色谱柱分离,以CO₂-甲醇/乙腈(体积比为1:1)为流动相进行梯度洗脱,通过质谱检测器测定、外标法定量.方法的最低检出限为0.07 mg·L,脂肪酸的加标回收率为90.50；～105.38；,相对标准偏差为0.81；～2.93；.结果表明,该方法灵敏度高、分离效果好、测定结果准确.

The Detection of Five Fatty Acids in Soybean Oil by Ultra Performance Convergence Chromatography-Mass Spectrometry

The 5 fatty acids in soybean oil were analyzed using ultra-performance convergence chromatography,including palmitic acid,stearic acid,oleic acid,linoleic acid and linolenic acid.The sample was dissolved by n-hexane after saponification reaction.The fatty acids were separated on the column of ACQUITY UPC BEH 2-EP by gradient elution with carbon dioxide and V(methano):V(acetonitrile)=1:1 system,and finally detected by MS detector.The limits of detection of target compounds in the method were 0.07 mg·L.The recoveries were from 90.50； to 105.38； at three spiked levels with the relative standard deviations lower than 3.0；.The method,with high sensitivity,good separation effect and high recovery,was successfully used to detect the underivatization fatty acids in soybean oil.