高温气相色谱-质谱联用法分析玉米油、掺杂油和煎煮油

Analysis of corn oil and its adulterated,fried and boiled oil by high temperature gas chromatography-mass spectrometry

用MXT-65TG金属毛细管柱研究了食用油中甘油三酯的高温气相色谱-质谱分析方法。考察了实验条件对分离检测的影响。根据质谱图中甘油三酯裂解的碎片离子[RCO]^+,[RCO+74]^+,[RCO+128]^+和[M-RCOO]^+,结合谱库检索,对食用油中甘油三酯组成进行定性分析。利用该方法,研究了掺杂不同比例的猪油时,玉米油甘油三酯谱图的差异,显示该方法可检测到玉米油中掺杂含量低至10%的猪油。对自制煎炸油和水煮油样品的分析显示,其中甘油二酯的相对含量逐渐升高。

High temperature gas chromatography mass spectrometry （HT-GC/MS） analysis method for the determination of triglyceride in edible oil was studied using MXT - 65TG （ 15 m × 0. 25 mm × 0. 10μm） capillary column. The effects of experimental conditions on the separation and detection were investigated. The composition of triglyceride in edible oil was identified according to their fragment ions （ [ RCO]^＋, [ RCO ＋ 74 ]^＋, [ RCO ＋ 128 ]^＋, and [ M-RCOO ]^＋） in the mass spectra of triglyceride combined with the mass spectra library. Using the method, the corn oil adulterated lard fat was determined and presented its difference to original corn oil, which suggested that 10% lard fat could be recognized. Triglycerides in home-made fried oil and boiled oil were also analyzed and showed the content of diacylglycerol increased in samples. The content of lard in corn oil as low as 10% could be detected by this method, and animal oil could be detected in swill oil.