金银花干制和冲泡过程中吡虫啉和啶虫脒的残留行为

为了研究金银花在干制和冲泡过程中吡虫啉和啶虫脒的残留行为,利用高效液相色谱法对其进行分析,结果显示,吡虫啉和啶虫脒在金银花和茶汤2种基质中的添加回收率为80.8%~94.5%,变异系数为0.5%~6.7%。晒干、阴干和烘干3种干制方法对金银花中的两种农药均有一定的消解作用,吡虫啉和啶虫脒残留的消解百分数分别为30.9%~78.3%和25.1%~78.0%,其中,晒干和高温烘干处理具有更高的消解百分数。在不同农药浓度、冲泡次数、茶水比和浸泡时间以及加不加盖子等冲泡条件下,金银花中的吡虫啉和啶虫脒残留分别有7.7%~26.3%和6.5%~39.4%转移至茶汤。可见合理的干制方法和冲泡条件可以减少吡虫啉和啶虫脒残留向人体的转移。

Behaviour of the imidacloprid and acetamiprid residues during the drying and brewing processes of Lonicera japonica

The behaviour of the imidacloprid and acetamiprid residuals during the drying and tea- brewing processes of Lonicera japonica were studied using high-performance liquid chromatography (HPLC). The recoveries of imidacloprid and acetamiprid ranged from 80.8% to 94.5% and the coefficients of variation (CV) were between 0.5%-6.7% for honeysuckle and tea infusion samples. Three drying methods (sun-, shade-, and oven-drying) had effects on the degradation of the two pesticides on honeysuckle. The degradation percents of imidacloprid and acetamiprid ranged from 30.9%-78.3% and 25.1%-78.0%, respectively, and digestion percents treated with sun-drying and oven-drying at a higher temperature were greater than those with shade- and oven-drying at a lower temperature. The pesticide concentration, tea/water ratio (TWR), number of infusions, tea brewing time, and covered or uncovered cups were investigated under different brewing conditions. The transfer percent of imidacloprid and acetamiprid were 7.7%-26.3% and 6.5%-39.4%, respectively. In conclusion, using appropriate drying methods and tea brewing conditions can reduce the transfer of imidacloprid and acetamiprid to humans.