Analysis of organochlorine pesticide residues by f

Analysis of organochlorine pesticide residues by gas chromatography

1. Preface

modern agricultural pesticides are widely used, with complex varieties and wide geographical distribution. The more developed the economy is, the more pesticides are used. The use of pesticides can increase production for its benefit; The use of pesticides pollutes the soil, pollutes drinking water, and has pesticide residues in food, which is harmful to public health and poses health risks. Weighing the advantages and disadvantages and eliminating the disadvantages are the central issues of the current impact of chemicals on the environment

due to the frequent use of pesticides, there may be pesticide residues on crops, especially their fruits. A recent survey conducted in the United States and Britain found that 73% of food crops could not detect pesticide residues, and the situation of vegetables and fruits was more serious. After harvest, some fruits need to be stored for a long time before they can be sold to consumers. Therefore, it is inevitable to use preservatives of fungicide type, and there must be pesticide residues in their skin and pulp

how about organochlorine pesticide residues in food in China? In 1992, China investigated the levels of organochlorine pesticide residues in basic dietary foods of Chinese people in Heilongjiang Province, Beijing, Sichuan Province, Zhejiang Province and Guangdong Province. Foods include eight categories that are most closely related to people: grain, vegetables, fruits, meat and poultry, aquatic products, plants, eggs and milk. Although the tensile testing machine of fiber products for six wadding is mainly used to detect the breaking strength of quilts and quilt covers filled with fiber for wadding, the residues of hexamethylene chloride and DDT in most samples do not exceed the Chinese residue limit standard; But BHC can still be detected in 69% of the samples; DDT was detected in 42% of the samples

although the production of BHC and DDT was stopped and banned in China in 1983, organochlorine pesticides are difficult to degrade and have a long service life. Now, dicofol is still used to kill insects on crops such as fruit trees and cotton. Its metabolite in the environment is DDE, which is quite similar in structure to DDT and has almost the same toxic effect. Therefore, the current polymerasia company was founded in Ho Chi Minh City in 2002, and the focus of crops is still on cracking down on organochlorine pesticide residues. This requires the determination of pesticide residues in crops

according to (gb/t17334 ⑴ 02-1998), the organochlorine pesticide residues in tea were analyzed by using 7890 Ⅱ gas chromatograph produced by Tianmei company, and good results were obtained

II. Experimental part

experimental instrument: techcomp7890 II gas chromatograph (Tianmei Scientific Instruments Co., Ltd.)

experimental conditions:

chromatographic column: ov-1701 or SE-54 30m × 0.32mm × 0.5um (Dalian zhonghuida Scientific Instruments Co., Ltd.)

detector: electronic capture detector (ECD)

column temperature: 200 ℃, sampler temperature: 220 ℃,

detector temperature: 220 ℃

carrier gas: high purity nitrogen, 8ml/min; Tail blowing: 16ml/min

range: 10, attenuation: 1 injection volume: 1ul