| Phthalate Acid Esters (PAEs) have known as plasticizers used in polyvinyl chloride (PVC) products. PAEs are recognized as environmental endocrine disruptors, which exerted a pernicious impact on human health, leading to reproductive and developmental toxicity. It was due to massive use of PAEs and disposal of consumer products containing phthalates at will, PAEs become ubiquitous environmental pollutants, which can be detected widely from the environment, such as water, soil and air. Once enter the environment, PAEs can easily work their way up food chains and bioaccumulate in animals and plants. In addition, PAEs in food-contact packaging can migrate into the food. Food intake is a major route of human exposure to PAEs, hence, it is necessary to estimate their health risk in food matrix.This paper studied 4 kinds of PAEs which had caused serious pollution to the environment. The SPE-GC methods were developed for determination of PAEs in vegetable, fish and cooking oil. The concentrations of 4 PAEs in different food sample was analyzed. According to the pollution level, the in vitro gastrointestinal model was carried out to analyze the bioaccessibility of PAEs, and the effect of some factors was analyzed. Combine with the metabolism obtained by in vitro experiments, risk assessment of PAEs in different food was analyzed. The results were as follows.(1) The GC and HPLC methods were developed. The method showed a good linearity with r>0.998. The LOD were in range of 0.09-0.16mg/L by GC method and 9.2-13μg/L by HPLC method. The methods could be chosen in the subsequent experiments.(2) An SPE-GC methods was developed for determination of 4 PAEs in vegetables, fish and cooking oil. The florisil column was used for purification in vegetable and fish samples. Through single factor experiment,2g florisil and 5 ml 30% ethyl acetate-n-hexane were used. The method showed a good linearity with r=0.998. The recoveries were in range of 66%-100%, and the relative standard deviations(RSDs) were lower than 7%. The PSA column was used for purification in cooking oil. The recoveries were in range of 80%-105%, and the relative standard deviations (RSDs) were lower than 7%. The result of the determination showed that PAEs were found in all food samples. The highest concentrations of PAEs were observed in one kind of oil packaged in plastic and ranged from 1.9648-5.5715mg/kg.(3) An in vitro gastrointestinal model was carried out to analyze the bioaccessibility of PAEs in different foods. The oral bioaccessibility of different PAEs were significantly different, ranged from 19.16%±2.84% to 87.51%±3.25%. The concentrations of 4 PAEs decreased significantly. In addition, the effect of some factors was analyzed, such as PAE concentration, residence time, bile salts, digestive organ and Kow. The results show that the bioavailability had no significant differences(p>0.05), while the concentration of PAEs changes within one order of magnitude. But other factors have significant influences on bioavailability.(4) The in vitro test was carried to study the metabolism of PAEs in serum different organs of mice and described the characteristics of metabolism. Through the t1/2 and Km from the tests, the speeds of the metabolism were significant different between male mice and female mice. The ability to metabolize PAEs for male mice was stronger than female mice. Serum and intestines have a fast metabolism than liver. The average metabolic rate of PAEs in different organs of mice followed the trend of:DEHP<DBP< DMP<DEP.(5) Two respects of risk assessment, the dietary exposure assessment and risk characterization, were calculated and discussed in the experiments. We could know from the pollution level and the risk quotient of major city that all of the food was considered safe. |
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