Determination of 16 Polycyclic Aromatic Hydrocarbons in Vegetable Oil by GPC and GC-MS/MS

A method for the determination of 16 polycyclic aromatic hydrocarbons in vegetable oil by gel permeation chromatography purification coupled with GC-MS/MS was developed. The results were shown below: (1) During GPC purification of soybean oil sample added with 16 PAHs, the distillates of 0~19 minutes were oil impurities. The distillates of 19~28 minutes and 28~36 minutes were collected in sections and then measured by GC-MS/MS. The results showed that the distillates from 19 to 28 minutes were PAHs of the first ten low molecular weight and the distillates from 28 to 36 minutes were PAHs of the last six high molecular weight. So, GPC was not strictly in the order of high molecular weight first peak and low molecular weight second peak. Therefore, in order to ensure the accuracy of the results, the method of segmenting collection and segmenting determination should be adopted when separating various compounds by GPC. (2) Compared with pretreatment method in GB/T 23213—2008, this method reduced the amount of vegetable oil sample weighed from 4.0 g to 1.0 g. The target analytes in samples were purified using GPC to eliminate most of the coextracts. The extraction process was simplified so that the possible content loss in the extraction process was avoided. The experiment time was shortened and the extraction reagent was saved. (3) The calibration curves of the 16 PAHs showed good linearity in the range of 10~200 ng/mL with the correlation coefficients(R2) greater than 0.99. The LOD ranged from 0.02 to 0.50μg/kg and LOQ ranged from 0.08 to 1.67 μg/kg for 16 PAHs. (4)At the spiked level of 20 μL, 40 μL and 80 μL the average recoveries were 85.30%~103.86%, 91.08%~106.71% and 88.01%~105.87% respectively, and relative standard deviations(RSDs) were 0.69%~2.93%, 0.64%~2.74% and 0.75%~2.81% respectively. The method met the requirements of 16 PAHs analysis.