Dissipation of Fipronil in Cabbage and Soils at Different Sites

Fipronil insecticide has biological activity against vegetable pests and been widely used in China recently.The present research probed dynamics of fipronil degradation in cabbage and soils at fields of Jinan and Kunming,respectively.The tests were carried out in this study to evaluate impact of using fipronil in ecosystem and to provide basic information for this insecticide.A quantitative study of fipronil residue by GC-ECD showed that dissipation of fipronil in the soil of Jinan(half-life approx.1.60 d) was faster than that of Kunming(half-life approx.4.9 d).But there was just only a slight difference in cabbage from these districts(half-life approx.0.7 d).In addition,the final residues of fipronil in cabbage were both lower than 0.0001 mg·kg-1 after 3 d treatment with a low dosage of the fipronil(26.25 g a.i.hm-2) to spray twice at interval of 3 d or after 7 d treatment to spray with three times application.