Analysis Method Study Of Urea Herbicides And Benzoylurea Insecticides In Food By Liquid Chromatography

With the development of society and agriculture, people pursue the largest agricultural production. Abuse pesticides problem is serious, so hazards of pesticide residue has aroused more attention. Pesticide classification from the application, including such as herbicides, insecticides and fungicides. This article established an analysis method about sulfonylurea herbicides, phenylurea herbicide and benzoylurea insecticides. In the chapter one, the literatures of urea herbicides and pesticides was reviewed. The herbicides’ harm, physical and chemical properties and analysis methods were introduced. Then the future of the detection for pesticide residues was prospected. In the chapter two, the urea herbicide was determined by microextraction flask-high performance liquid chromatography in tea drinks. Herbicides were separated on C18 column and determined using UV detector at 230 nm. The regression equations of Primisulfuron-methyl and linoron were determinated in blank real samples, and the linearity was good in the range of 60-6000 ng/m L with the correlation coefficients more than 0. 9993. The average recoveries were 74.83% and 98.67% respectively. The relative standard deviations were less than 1.8%.The MDL is 50μg/L. In the chapter three, the urea herbicide in canned sweet corn was determined by matrix solid-phase dispersion- liquid chromatography. The effect of separation conditions, dispersants species, the mass ratio of dispersant to sample, et al were researched. The average recoveries of linuron and flucarbazone-sodium were 94.49% and 87.80% respectively. The relative standard deviations were less than 1.08% and 1.62%, the MDL are 54ng/g and 108ng/g respectively. In the chapter four, subzero-temperature frozen extraction using acetonitrile as a solvent was applied to the extraction of pesticide such as tribenuron, primisulfuron, hexaflumuron, teflubenzuron, Triflumuron from flavored milk drinks. HPLC was used for determination. Acetonitrile was used as extractant under-18℃. Salt effect, frozen time and the volume ratio of extraction agent to sample were studied. Under the optimal conditions, the linear regression equations offive kinds of pesticide were good and the correlation coefficients were more than 0.9994.The relative standard deviations were less than 2.33%.The recovery of the target analyte were between 92.3%-98.7%.