作　　者： ; ; ; ; ; ; ; ;

机构地区： 上海大学环境与化学工程学院环境污染与健康研究所

出　　处： 《科学通报》 2009年第4期441-447,共7页

摘　　要： 采用体外实验研究了胡萝卜中p,p′-DDT,p,p′-DDD和p,p′-DDE(总称为DDTs)在模拟人体胃肠中的消化特征及其稳定碳同位素效应.结果表明,在消化过程中,DDTs从胡萝卜中的释放遵循伪二级动力学过程.模拟液和胡萝卜基质质量比对释放过程有影响,比值越高,释放越多,两者呈对数关系.由于模拟液的pH可以影响胃蛋白酶的活性,对DDTs消化有影响,但DDTs在胡萝卜中的浓度对消化释放没有影响.在所有这些过程中,残留在胡萝卜中的DDTs其同位素不变,即DDTs在这些消化过程中不会发生同位素分馏.采用体外实验研究有机污染物在人体胃肠系统消化过程的同位素效应,为采用体外实验研究生态环境中的食物链示踪提供了新的研究思路. The character and stable carbon isotope effect of p,p′-DDT, p,p′-DDD and p,p′-DDE （referred to as DDTs） in the polluted carrot were analyzed using a physiologically based in vitro test by simulating the human gastro-intestinal tract. The study results showed that the release process of DDTs from carrot followed the pseudo-second-order equation during digestion. The ratio of the solution to the food matrix affected the release of DDTs from carrot. The higher the ratio is, the more the DDTs will be released. A logarithmic relationship was found between the ratio and the food matrix. The pH value of the digestion solution had significant effect on the DDTs release due to the effective enzyme activity of pepsin. However, the levels of DDTs in carrot had no influence on them. The isotopic composition of DDTs in the carrot after digestion did not change during the digestion under all the conditions. It meant that there were no significant carbon isotopic fractionations during digestion. This is the first report demonstrating the isotope effect of organic compounds during stomach and small intestine digestion. In addition, the present study provided a new idea for food chain source tracing in ecosystem using in vitro test.

关 键 词： 体外实验 滴滴涕 同位素 分馏 消化

领　　域： [环境科学与工程] [理学] [理学]