Study On Pollution Characteristics Of Polycyclic Aromatic Hydrocarbons In Edible Vegetable Oil Processing

This paper developed a gel permeation chromatography(GPC) and dispersed solid phase extraction(DSPE) combined with gas phase chromatography- mass spectrometry(GC-MS) method for polycyclic aromatic hydrocarbons(PAHs) in edible vegetable oil. And we systematically investigated the pollution characteristics of polycyclic aromatic hydrocarbons(PAHs) in edible vegetable oil, crude oil of edible oil and refining process, in order to study its dynamic change and transformation mechanic in the process of oil. The main contents are as follows:(1) A method of simultaneous detection 16 PAHs of edible oil by gel permeation chromatography(GPC) and dispersive solid-phase extraction(DSPE) combined with gas phase chromatography- mass spectrometry(GC-MS) method was established. And the matrix effects of the prior 16 kinds of polycyclic aromatic hydrocarbons(PAHs) were evaluated in 7 edible vegetable oil from oil seeds. From the results, the obviouse matrix strength effect was found in all 7 different vegetable oils although there are a little difference among these 16 target compounds. The average recovery rate of 16 PAHs in edible vegetable oil was 60.9%–104.3%.The limits of determination(LOD) estimate with 3 times of signal to noise ratio for all target analytes were between 0.001 μg/kg to 0.25 μg/kg. The limits of quantification(LOQ) were estimated with 10 times of signal to noise ratio.(2) The concentration levels of polycyclic aromatic hydrocarbons(PAHs) were investigated in five edible vegetable for crude oil plants in China. And the changes of the concentrations of PAHs in the processing were also study. The concentrations of PAHs in peanut and soybean crude oil concentration were increased along the processing stages, which may be related to the temperature and time in the process of crude oil.(3) The concentration levels of polycyclic aromatic hydrocarbons(PAHs) were investigated in seven refining processing for edible vegetable plants in China. Degumming, depickling, decolorization and deodorization were the key point of oil refining process in the worldwide in recent years. In this processing, the concentration levels of PAHs in deodorization oil decreased significantly, indicating that refining process can remove PAHs in the processing. Baed on the concentration change of PAHs in refining process, the crude oil and depickling processing stages were selected as the key control points.(4) The concentration levels of the prior 16 kinds of PAHs were determined in edible vegetable oil samples from the marked of Beijing. The sum concentrations of 16 kinds of PAHs were ranged from 1.46 μg/kg to 303.16 μg/kg suggesting that the pollution of PAHs was common and popular in edible oil in Beijing. And the order of concentrations was sesame oil > peanut oil > sunflower oil > blend oil > olive oil > soybean oil > corn oil. According to the risk assessment, the value of ∑8PAHs/∑16PAHs were far less than 1, which indicated that the risk of PAHs in edible oil was acceptable for to Beijing residents.The above results showed that the polycyclic aromatic hydrocarbons(PAHs) were popularity in edible vegetable oil. And the concentration levels were in the acceptable range in the brand vegetable oil in Beijing, which was lower than the limits of PAHs in edible vegetable oil. And the PAHs were produced in the crude oil processing which lied on the temperature during the processing. And according to the concentration change of PAHs in refining process, the crude oil and depickling processing stages were selected as the key control points.