烟碱类农药吡虫啉的体外经皮渗透实验

Study on dermal absorption of Imidacloprid in vitro

目的研究吡虫啉体外经皮渗透吸收的效果，分析样品浓度和皮肤蓄积作用等对农药风险评估的影响。方法采用Franz垂直扩散池，以雄性Wistar大鼠离体腹部新鲜皮肤或冷冻皮肤为渗透屏障，LC／MS／MS法测定接受液和皮肤中的吡虫啉含量，分别比较高低两种吡虫啉溶液和两类皮肤的透皮效果。结果在使用新鲜皮肤的体外试验中，高、低两种浓度的接受液中吡虫啉含量占总受试物的比例均数分别为6．8％，6．6％，皮肤残留中吡虫啉含量占总受试物的比例均数分别为10．7％，1．3％，经皮渗透吸收率为分别17．5％和7．9％。在使用同种（低浓度）浓度新鲜和冷冻皮肤的体外试验中，新鲜皮肤和冷冻皮肤的接受液中吡虫啉含量占总受试物的比例均数分别为6．6％，0．7％，皮肤残留中吡虫啉含量占总受试物的比例均数分别为1．3％，10．7％，经皮渗透吸收率分别为7．9％和11．4％。结论高浓度吡虫啉在新鲜皮肤上的经皮渗透吸收率最大，是本实验吡虫啉暴露“最坏情况”的估计值，也是可用于风险评估的参考值。

Objective The dermal absorption of Imidacloprid was studied to understand the effects of concentrations and skin reservoir on pesticide risk assessment in in vitro absorption studies. Methods By using Franz diffusion cell and the transdermal barrier of viable Wistar rat abdomen skin or frozen ones, the imidacloprid content in the receptor fluid and skin was determined by LC/MS/MS method, and the absorption effects were compared between two concentrations of Imidacloprid solutions and two types of skin, respectively. Results All percentages reported are % of applied dose. In vitro studies using viable skin, the [midacloprid content in the receptor fluid of high and low concentration was 6.8%, 6.6% respectively; and 10.7%, 1.3% in skin, thus total absorption was 17.5% and 7.9%.And in vitro studies using both viable and frozen skin under the same concentration circumstances, the Imidacloprid content in the receptor fluid of viable and frozen skin was 6.6% and 0.7% respectively, in skin was 1.3% and 10.7%, and total absorption was 7.9% and 11.4%. Conclusion Comparison of these in vitro results showed that either concentrations or skin reservoir had an effect on the dermal absorption. During 6h exposure, the high concentration in viable skin had the maximum dermal absorption value, which was the worst-case exposure estimate, also the best single estimate for pesticide risk assessment.