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Pyrethroid pesticides commonly used in vegetable production efficiency, broad-spectrum, low toxicity pesticides. In agricultural products quality and safety testing their residues exceeding the problems have occurred, systematic study of pyrethroid pesticide residues in vegetables and digestion law has important practical significance to promote the safe production of vegetables. The selection of tests cypermethrin, fenvalerate, deltamethrin three commonly used pyrethroids, the establishment of three pesticide residue analysis by gas chromatography method and system of the three pesticide spraying dose, application The number of spraying pesticide residues in cowpea, Brassica juncea, and red flower stalk three vegetables regular, quantitative assessment of these commonly used pesticide application security. The results are as follows: 1. The gas chromatography Methods: with u-ECD Agilent6890N gas chromatograph and HP-5 capillary column, the simultaneous determination of pesticide residues of vegetables in three. Measurement results: a linear relationship between the content and the peak area of three pyrethroid pesticides, three pesticides in the three vegetables average recovery range between 86.5 to 98.6%, coefficient of variation in the range of 2.3 to 7.8 %, and the minimum detection concentration range of 0.002 ~ 0.005mg/kg, this method has a high degree of accuracy and precision. The test results show that the detection method of the present test it is possible to detect these three residues of pesticides in vegetables. 2. The pesticide degradation dynamics: different pesticides in different vegetables and the same vegetables in different parts of digestion law of the same. The half-life of cypermethrin in cowpea leaves, cowpea fruit, Brassica juncea, beetroot sprouts were 3.15d, 2.63d, 2.95d, 3.09d, fenvalerate 4.85d, 3.63d, 3.54d, 3.97d, bromine cyanide permethrin were 3.01d, 2.77d, 2.61d, 3.23d. 3. The spraying dose of pesticide residues in the relationship: pesticide residues in vegetables was positively correlated with the dose of pesticide applicators. Under control and its comprehensive consideration of food safety of the vegetable production in the application of cypermethrin, fenvalerate, deltamethrin dose should be commonly recommended dose to a maximum recommended dose of three pesticide applicator dose was 20 ~ 30ml/667m ~ 2,15 ~ 40ml/667m ~ 2,20 ~ 40ml/667m ~ 2. When sprayed with the highest recommended dose, 30ml/667m 2 Spraying dose spraying cypermethrin, cowpea fruit, 3d is safe harvest period; Brassica juncea, 9d is safe harvest of red flower stalk; , 5d is safe harvest period. With 40ml/667m to fenvalerate dose of pesticide spraying in cowpea fruit, 7d is safe harvest period; red flower stalk is safe harvest period, 11d, and Brassica juncea after spraying 11d residues still higher than the maximum allowable residues. With 40ml/667m deltamethrin spraying in the cowpea fruit and red flower stalk, 3d meet the safe harvest period; Brassica juncea, 7d is safe harvest period. 4. The frequency of administration and the relationship of pesticide residues in the number of pesticide applicators: vegetables have a certain impact on the final residue of the pesticide. Two treatment application of pesticide residues on vegetables greater than a pesticide treatment, with the passage of time after application of pesticide residues in vegetables in the same interval twice during treatment application process the difference is getting smaller and smaller. Thus, increasing the frequency of administration should be extended to the safety of vegetables harvest period. 5. Different varieties of the same vegetables with pesticide residues: different varieties of the same vegetable is relatively small impact on the final residue of pesticides. Spraying dose of of 60ml/667m to early maturing cowpea in Shandong, Du in cowpea, processing seven
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