Research On The Preparation Of 30% Carbosulfan·Acetamiprid Water Dispersible Granules

WG(water dispersible granule) is a new particle formulation in the 1980s made on the base of suspending agent and wettable powder which conquers a lot of Problems that the powder of wettable powder polloutes environment and the stabilization of physical chemistry characters of suspending agent is not very good.But it is more popular because of their packaging and easy to use,uniform particle size and smooth,not bonded with each other in the storage of high temperature and high pressure conditions,high levels of active ingredients,physical and chemical stability,bucket of water in the spray dilution that can spread quickly.So WG has a lot of advantages and rivalrousness in all pesticide formulation.In this study,we use the interactive method to screen for the best ratio and calculate the toxicity ratio of different proportions mixture.Then we choose the group which toxicity ratio is greater than 1.25 to conduct toxicity measurement,further calculated toxicity regression equation and LC₅₀ values and finally obtain co-toxicity coefficient(CTC) using the method of Sun(1950).On the basis of having selected the best mixture ratio,we conduct a variety of auxiliary screening experiments and obtain the preferential prescription of 30%Carbosulfan·Acetamiprid WG.And then the quality analytical methods was established,the product was used to control cabbage aphid in field trials.The main results could be summarized as follows:1 Determination of ToxicityUsing the leaf dip method raised by IRAC,Median lethal concentration of Carbosulfan and Acetamiprid against cabbage Myzus persicae(sulzer)was tested.The experimental results show that Carbosulfan's LC₅₀ is approximately 83.24 mg / L and Acetamiprid's LC₅₀ is approximately 11.50 mg / L.The initial screening of the best ratio was performed with interactive method and the toxicity ratio of different proportions mixture was calculated,the results indicate that the groups six to nine which toxicity ratio is greater than 1.25 show synergized action.Then we calculated the CTC of the four groups.Test results show that the Co-toxicity coefficient of nine is highest up to 213.26,which the mass ratio of carbosulfan and Acetamiprid is about 2:1. 2 Determination of the preferential prescription of 30%Carbosulfan·Acetamiprid WG and its Small-scale test productionmethodsBased on the best mass ratio 2:1 mixtures of carbosulfan and Acetamiprid was fixed on,Various auxiliary Screening experiments were performed,the main factors of product quality were explored and the best small-scale test method of production was found.The Ultimately determined preferential prescription is that Carbosulfan(Pack 100) 20%, Acetamiprid(Pack 100) 10%,silica 25%,Terspers 2700 6%,K12 2%,Terwet 1004 2%,Urea 4%, Sucrose 1.5%,SUZ-7 3%,Citric acid 0.02%,Soluble Starch make up 100%.The Ultimately determined small-scale test method of production is that after the crude oil of carbosulfan was totally adsorbed by white carbon black,The weighed Acetamiprid TC,soluble starch and other additives were added and mixed.Crushed by the jet mill,the aqueous solution that contains binder was added.The mixture was mixed in Kneader to be a plastic shape,extruded granulation,then dry in oven at 40℃for 2～4h.Sift with 10 and 50 mesh screen and Shaped.Detection the moisture content to be qualified,then we get the final products.3 The quality testing and analysis method found of 30%Carbosulfan·Acetamiprid WGReference to related national standards,the wettability,Suspension rate,disintegration,dispersion, Particle size distribution were tested.The results show that the samples are cylindrical light yellow particles,suspension rate of the production is 92.08%,the dispersion time is 16s and the disintegration time is 59.3s.Tbe water content is about 0.67%.The pH is about 6.85.The decomposition rate of Carbosulfan and Acetamiprid after heat storage at 54±2℃within 14 days were 3.47%and 2.16%.Test results show that the detection of targets in line with national requirements.The detection method of 30%Carbosulfan·Acetamiprid WG using HPLC was established. Operating conditions are as follows,Column temperature:25℃;Flow:1.0mL/min;Detection wavelength:254mn;Mobile phase:methanol + water + acetonitrile = 20 +60 +20,degassing with membrane filter;Sample volume:20μL;RP-C18 column.This method can be used to separate the two active ingredients and impurities in 30%Carbosulfan·Acetamiprid WG,and have better accuracy and precision.Meanwhile it can objectively and accurately reflect the quality of products.So it can be used for the determination of the product 30%Carbosulfan·Acetamiprid WG to judge whether the content is qualified. 4 Field trials of 30%Carbosulfan·Acetamiprid WG against Cabbage Myzus persicae(sulzer)Test set up the following eight treatment groups,30%Carbosulfan·Acetamiprid WG 20mg/L,30 mg/L,40 mg/L,50 mg/L,60mg/L;20%carbosulfan EC 100mg / L;20%Acetamiprid WG 30mg / L and water control.We can see by the test The treatments of 30%carbosulfan Acetamiprid WG 30 mg/L,40 mg/L,50 mg/L,60 mg/L have a good control effect against cabbage Myzus persicae(sulzer).It has a similar effect compared with the corresponding products which has officially registered.In test concentrations,we found no symptoms of phytotoxicity.The concentration recommended in the production is 30 mg/L～60mg/L.