Study On Fast Detection Technique For Organophosphorus Pesticides And Its Application

Organophosphrous pesticides are widely applied to agricultural field instead of organochlorine pesticides, such as DDT, because of their high effectiveness, broad spectrum, low toxicity and esay to degrade biologically. However, these pesticides have also caused undesired consequence to the environment and human health, especially affected the quality security of agricultural products directly. Therefore, it is a hot spot that the public concern to detect the residue of them, especially rapid detection for them in vegetables. Conventional methods for detecting residual organophosphorus pesticides, including chromatography, mass spectrometry, spectroscopy, they are time-consuming and costly, and are hard to satisfy the increasing requirements of the online detection.Enzymatic inhibition method is a fast detection method for the pesticide residue in vegetables and fruits. Compared with traditional chemical anlysis and instrumental analysis, it overcomes some disadvantages, including long analytical time and high cost. Its advantages are directly, simple and sensitive, and can detect a large number of samples at short time, so that it can screen many superstandard samples within a relatively short time and shorten detection range. The rapid determination method for pesticide residues can keep some highly residual vegetables and fruits out of the markets, and avoid to happen toxic case, thus the consumers' health can be protected.Based on the mechanism which organophosphorus pesticides can inhibit activity of acetylcholinesterase, we first used methylcellulose as carrier to prepar potential biosensor in this thesis. In this study, some immobilization conditions, including the concentration and dosage of methylcellulose, the mixture ratio of methylcellulose and DMF, the content of acetylcholinesterase, the concentration of substrate solution and the immobilization time of enzyme, has been investigated, and some factors which can effect on working of enzymatic electrodes, for instance, pH of substrate solution, the time of enzymatic reation and the working environment of the electrode, has also...