Residue Measurement Of Pendimethalin And Metolachlor In Soybean Using Solid Phase Extraction And HPLC-UV

Pesticides residue can be a serious problem in agricultural production regions,which has a firm relationship with the health and safety of human beings and environment . For protecting human beings and environment, the detailed investigation into the pesticide residue is very important. People have done a lot of research work to develop the detection technology of pesticide residues.The subjects of this research is pendimethalin and metolachlor, which is commonly used pesticides.They have been widely used to control annual grasses and broadleaf weeds in a large variety of vegetables and crops. They are easily absorbed by plants with the soil and water.Accumulated in plants, they will directly enter the human body ,result in health threats.In this thesis, the samples prepared method is solid-phase extraction,detection techniques is high performance liquid chromatography whit UV detector. This work have established a rapid detection method of pendimethalin and metolachlor in soybean, meeting the relevant demand for pesticide residues.The thesis is divided into five parts. Chapter1 is the background information, including the definition of pesticides and pesticide residues ,which relate to the danger of pesticide residues. Further, reviewed the samples prepared method and the research progress, including extraction techniques, such as ultrasonic extraction, microwave assisted extraction, accelerated solvent extraction, and purification techniques, such as supercritical fluid extraction, solid phase extraction, solid phase micro-extraction and so on. Then, make a conclusion for the research progress of detection methods, including gas chromatography, liquid chromatography, biological detection and so on. Chapter 2 established a rapid detection method for pendimethalin by solid phase extraction - high performance liquid chromatography whit UV detector . improve the extraction efficiency by a new solid phase extraction column.This work makes an achievement that saves the samples and organic solvents . After the method optimization, this work got a satisfactory purification efficiency and the extraction recovery.The average recovery were 86%-97.5%,RSD<8.36%,The LOQ and LOD were 1.0-10.0 mg/L and 0.075 mg/L. The actual test results meet the standard of required analysis.Chapter 3, established a rapid detection method for metolachlor by SPE - HPLC, The work optimizes chromatographic conditions, extraction conditions, clean condition, and the sample preparation conditions . After the method optimization, average recovery was76.0%-99.1%,RSD<9.45%,The LOQ and LOD were 0.2-1.0 mg/L and 0.061 mg/L. The actual test results meet the standard of required analysis.Chapter 4, according to the development trend of pesticide residues , This work established a method for pendimethalin and metolachlor detection at the same time ,based on the detection of the two kinds of Pesticides respectively . It is a less organic solvent and more environmentally friendly method for pendimethalin and metolachlor detection . After the method optimization, the work got a satisfactory purification effect and extraction recovery. The average recovery were44.0%-114.0%,RSD<17.4%,The LOQ and LOD were 0.2-10.0 mg/L and 0.061-0.075mg/L.The actual analysis of test results meet the required standard.Chapter 5 summarized the conclusion of the work.Pointing out the advantages in application.