Abstract:

【Objective】 The objective was to study the application of environment-friendly solvent, biodiesel as substitute solvent, in preparing the lambda-cyhalothrin microemulsion, and to provide a reference for biodiesel widely used in green pesticide preparations. 【Method】 Using phase transfer method, three 2.5% lambda-cyhalothrin microemulsions with different solvents of biodiesel, cyclohexanone and 0# diesel were prepared. The phase behavior, toxicity to Aphis gossypii Glover and larva of Pieris rapae, and the safety to cotton of the formulation with different solvents were compared. 【Result】 Biodiesel had good dissolving ability to Lambda-cyhalothrin, could reach 326 g?L-1 under 25℃. The microemulsion with biodiesel as solvent had transparent appearance, good low-temperature performance, and the decomposed ratios of active ingredients only 2.0% after 14 days storage at 54℃. The LC50 values to A. gossypii Glover and 3rd larva of P. rapae had no difference among the three formulations prepared with different solvents, and had no effect on the shoot height and total chlorophyll content of cotton seedlings. 【Conclusion】Good lambda-cyhalothrin microemulsion formulation could be prepared with biodiesel as the solvent, the biodiesel has no negative effects on the activity of active ingredients, and is comparatively safe to cotton seedlings.

Key words: bodiesel, solvent, microemulsion, lambda-cyhalothrin