吡虫啉在茶叶和茶园土壤中的残留研究

研究了吡虫啉在茶叶和茶园土壤中的残留分析方法及残留动态。样品采用二氯甲烷超声提取,中性氧化铝层析柱净化,反相液相色谱测定,方法的添加回收率鲜叶为75.8%~89.1%,土壤为81.8%~105.1%,变异系数分别为3.8%~5.5%和5.0%~5.9%,最低检测浓度鲜茶叶为0.01 mg/kg,土壤为0.003 mg/kg。吡虫啉在鲜茶叶和土壤中的半衰期分别是1.9~2.2 d和3.7~2.8 d,在鲜茶叶中的降解速度快于在土壤中的降解速度。

DEGRADATION DYNAMICS OF IMIDACLOPRID IN TEA LEAVES AND TEA GARDEN SOIL

A determination method of the residue and degradation dynamics of imidacloprid in tea leaves and in tea garden soil are described in this paper. Samples of fresh tea leaves and tea garden soil were extracted with dichloromethane, and the extracts were purified on aa Al2O3 column, followed by imidaclopfid determination using HPLC with a DAD detector. The recovery rate was 75.8% to 89. 1% for fresh tea leaves and 81.8% to 105.1% for the soil, with a V. C. of 3.8% - 5.5% and 5.0% - 5.9%, respectively. The minimum detectable concentration was 0.01 mg/kg for tea leaves and 0.003 mg/kg for the soil. The degradation half-life of imidacloprid was 1.9 - 2.2 days for tea leaves and 3.7 - 2.8 days for the soil, thus the degradation speed being faster in tea leaves than in the soil.