Application Of Chromatography Technology In Quality Evaluation Of Edible Vegetable Oil

Edible vegetable oil is a major component of human diet and one of the seven major nutrients tothe survival of humans which can provide necessary energy for human life activities. However, theadulteration of edible vegetable oil was happened frequently at present, so establishing a qualitydetection for edible vegetable oil can not only control the quality of edible vegetable oil, but alsoeffectively ensure the safety of consumers.This study established a method to detect the main components of fatty acid and triglycerides inedible vegetable oil by chromatography mass spectrometry, and analyzes the types and contents of fattyacid and triglyceride in some common vegetable oils (soybean oil, corn oil, peanut oil, sunflower seedoil and olive oil). In addition, a detection method of detecting residual solvent-a common kind ofxenobiotic pollutant in vegetable oils was improved based on the standard.(1)According to screen the chromatographic column system, optimize the parameters likemodulation period, thermal spray time, air conditioning and so on, it was the first time to apply GC×GC-MS technology to the determination of fatty acid in vegetable oil in China, and the sensitivity ofthis established method is better than the traditional gas chromatography analysis method. The resultsdemonstrated that the separation was achieved in50min with the column set of DB-1(30m×0.25mm×0.25μm) as the1st column and DB-Wax (3.2m×0.1mm×0.1μm) as the2nd column. All fatty acidswere accurately and sensitively determined while the modulation period was3.5s and the scan range ofquadropole MS was m/z40~350.(2)Vegetable oil was diluted to3%by isopropyl alcohol-acetonitrile solution with1:1bulk factor,and at the condition that the column temperature was35℃and the temperature of sample room was15℃, took the BEH C18chromatographic column (5μ m,4.6mm×250mm) and isopropylalcohol-acetonitrile solution as mobile phase elution to separate the analysis. Qualitative analys is of28triglyceride compositions were according to the ion fragmentation information obtained throughESI-Q-ToF and quantitative method was area normalization, took LnLnLn and PPP as the reference, thelimits of detection were8~10mg/g. The results by analyzing of the types and contents of5kinds ofvegetable oil triglycerides demonstrated that OOO was the feature TAG of extra virgin olive oil, LLLnwas the feature TAG of soybean oil, and the main triglycerides in virgin olive oil were OOO and POO,while in the other4kinds of vegetable oil were LLL, OLL and PLL as the major component oftriglyceride the.（3）An national standard method for detection of an xenobiotic-No.6solvent in vegetable oil bygas chromatography was improved, the automation degree was higher than original method, and theaccuracy of the method was also increased by introduction of internal standard. Headspace samplingafter shaking30min at60℃, the analysis were then detected by FID detector after separation by HP-5(0.25μm,0.25mm×30m) chromatographic column. Tooking N-heptane as internal standard and the totalpeak area of No.six solvent as analysis, carrying on quantitative analysis by Standard curves of internal standard area normalization method. This method was with wide linear range (10~200mg/kg), highprecision, good repeatability, high accuracy and the limits of detection is2mg/kg.The analysis method above has the advantages of simple operation, high degree of automation,good reproducibility, high sensitivity, and provided a theoretical basis for vegetable oil supervisiondepartments and related workers.