The Study Of The Applicaiton Of Evironmental Firendly Solvents In The Preparation Of Spirodiciofen EW

The emulsion of oil in water (EW) is one of the new developedpesticide formulations. The technical agrochemicals (insoluble in water) aresuspended or dispersed in water by the action of dispersant, emulsifier and otheradditive agent. The average droplet particle size is less than2μm in EW. Theemulsion in water uses water as dispersing medium. As environmental friendlyformulation, EW is accepted by people.But at the present, aromatic solvents to dissolve the pesticide active ingredients inthe preparation of EW are still used. The EW prepared in the traditional solvents andmethods still has adverse ecological environmental impacts.This paper studied the application of environmental friendly solvents and its mixedsolvents in the preparation EW. The properties of the products we prepared werecomprehensively evaluated (such as appearance, stability, dispersedness, dilutionstability, hot storage stability, low temperature stability, particle size etc.). And wefound the best environmental friendly solvents used in the preparation of10%spirodiclofen EW.In this paper we studied:1. The screen of emulsifiers suitable for the preparation of spirodiclofen EW:EW-36, BT-508, NP-10-P, E600,5030,5038etc emulsifiers were used in the prepar-ations of spirodiclofen EW with environmental friendly solventA, B, C, benzene, me-thylbenzene, dimethylbenzene, S-200#etc solvents respectively. We found the EW-36was the most suitable emulsifier in the preparation of spirodiclofen EW by checkingthe dispersedness, hot storage stability, low temperature stability, particle size etc ofthe preparation.2. The study of the application of the environmental friendly solvents and its mixedsolvents in the preparation of spirodiclofen EW: We prepared10%spirodiclofen EWusing EW-36as emulsifier and environmental friendly solvents and theirs mixedsolvents. We found that total properties of the preparation of10%spirodiclofen EWmade by the mixed solvent of S-200#and xylene (5%xylene) were qualified; thepreparation of10%spirodiclofen EW made by the mixed solvents of environmentalfriendly solventA, B, C with8-9%xylene exhibited best preparation properties andthe hot storage stability of the preparation became bad when the dosage of xylenereached12%. 3. The determination of particle size of the preparations: We determined the particlesize of the preparations we made. We found the preparations had the least particlesizes when using S-200#as solvent and5030and5038as emulsifiers respectively. Wealso found that the preparations using the same emulsifier with different solvents hadthe almost same particle size.4. The determination of hot storage stability of the preparations: We determined theactive ingredient contents of the preparations we made after hot storage by HPLC(Inertsil ODS-3column (250mm×4.6mm，10μm)，methanol-water=91：9，1.0ml/min，254nm，10μl injection). The determining results showed that after hot storagethe active ingredient content in spirodiclofen EW we prepared is qualified.5. The filed trial of10%spirodiclofen EW we prepared to control spider mites inapple trees: We carried out the filed trial of10%spirodiclofen EW we prepared tocontrol spider mites in apple trees. The contrast agent was24%spirodiclofenSC(manwei). The result indicated that10%spirodiclofen EW we prepared at5ppm tocontrol spider mites in apple trees had the equivalent efficiency with24%spirodiclofen SC(manwei) at4.8ppm, and the control efficiency of10%spirodiclofenEW we prepared was a little bit better than24%spirodiclofen SC(manwei).