Fast microencapsulation of chlorpyrifos and bioassay

Abstract

The objective of this work was to explore the possible efficient application of pesticides in an environmentally friendly way. The present paper reports the preparation, characterization and bioassay of chlorpyrifos-containing microcapsules. With trimer of isophorone diisocyanate and triethylenetetramine as wall-forming materials, sodium dodecylsulfate and xanthan gum as stabilizers, and an emulsifying speed of 3000 rpm for 12 min, chlorpyrifos-containing microcapsules, with a diameter ranging 2-7μ m and an initial encapsulation rate of 94.7%, were prepared by fast interfacial polymerization at room temperature. Formulations based on the prepared microcapsules are stable in neutral medium and release chlorpyrifos in both acidic and alkaline media. The results of bioassay against 3rd-instar Spodoptera litura larvae showed that microcapsule formulations had more sustainable efficacy than that of conventional emulsion formulations. The idea and approach presented in this work have potential application in the pesticide industry. © Pesticide Science Society of Japan.