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Keywords: organophosphorus pesticides initially pesticide residue detection technology is limited to chemical method thesis colorimetric and bioassay method thesis detection methods lack of specificity thesis sensitivity is also not high. the 1960s the application of gas chromatography in the analysis of pesticide and drug residues thesis has greatly improved the pesticide and drug residue The application of gas chromatography to the analysis of pesticide and drug residues in the 1960s greatly improved the quality of pesticide and drug residue analysis.

Abstract:

Keywords Organophosphorus pesticides Initially, pesticide residue detection techniques were limited to chemical, colorimetric and bioassay methods, which lacked specificity and sensitivity.In the 1960s, gas chromatography was applied to the analysis of pesticide and drug residues, which greatly improved the detection of pesticide and drug residues.Since the 1980s, high-performance liquid chromatography has been widely applied to the analysis of pesticide residues. Since the 1980s, high performance liquid chromatography (HPLC) has been widely used in the analysis of thermally unstable and ionic pesticides and their metabolites. Although the chromatographic method is accurate and sensitive, it requires expensive equipment and professional operation, and the long analysis time is not conducive to on-site monitoring. In this paper, the current pesticide and drug residues rapid detection of analytical techniques to explore the progress of an overview. 1 light-emitting bacteria detection technology Exploration shows that different types of light-emitting bacteria have the same luminescence mechanism [1]. That is, the efficacy of molecular oxygen, intracellular luciferase catalyzed by the reduced state of flavin nucleic acid (FMNH2) and long-chain aliphatic aldehydes oxidized to FMN and long-chain fatty acids, and at the same time release the maximum luminous intensity at a wavelength of 450 ~ 490nm blue-green light. Commonly used luminescent bacteria are some bacteria of the genus Vibrio and Luminescent bacillus. Yuan Dongxing [2] and others used luminescent bacteria to rapidly detect the residues of organophosphorus pesticides in vegetables, through the light-emitting bacteria on several organophosphorus pesticides in the vegetables of the inhibition of the light reaction, the results of luminescence intensity and the concentration of organophosphorus pesticides in the sample was negatively correlated, and the minimum limit of detection can be up to 3mg/L. At present, luminescent bacteria detection technology is widely used in environmental monitoring and food safety testing, and its safe testing in the food. It is mainly used in the detection of pesticide and veterinary drug residues, heavy metal biotoxicity detection, etc. [3], the method is fast, simple and sensitive. However, after the activation of luminescent bacteria, its luminous intensity will change with the change of time, resulting in unstable detection results. In addition, due to the complexity of the components in the food, the concentration of pollutants is low, the detection instrument can not reach such a low detection limit, so the use of this method in food safety detection is not common. 2 chemiluminescence technology chemiluminescence (CL) is a luminescent substance luminescence (Luminol), gallic acid (Gallicacid), etc. and organophosphorus pesticides to carry out a number of extraordinary chemical reactions, the reaction of the reaction of the intermediate or reactant to absorb the reaction of the chemical energy released by the excited state and jump to the excited state, when they return to the ground state from the excited state will occur when the light radiation, photons through the photomultiplier and the amplifier. After passing through the photomultiplier tube and amplifier, the photons are transformed into current and amplified, and the current size is proportional to the concentration of organophosphorus under certain conditions [4]. There are four detection methods based on the reaction principle: (1) CL method for acetylcholinesterase inhibition; (2) catalytic CL method for alkaline phosphatase; (3) method for the reaction between peroxides and indoles; and (4) method for the reaction between luminal and hydrogen peroxide (H2O2). The chemiluminescence method was used for the detection of organophosphorus pesticides, and the detection limit could reach the level of ng/kg class.Ayyagari [5] detected leuco based on the fact that alkaline phosphatase can catalyze the dephosphorylation efficacy of phosphate-containing compounds, i.e., the leuco inhibits the activity of phosphatase and produces a weak luminescent signal to detect leuco, and the limit of detection was 500 ng/L.Rao [6] et al. performed a reaction of the lumenol-H2O2 system on the Rao [6] et al. carried out chemiluminescence analysis of organophosphorus pesticide - methyl parathion with lumino - H2O2 system, found that polyethylene glycol has significant sensitizing effect on the reaction, and established the method of flow injection chemiluminescence (FIA-CL) for the determination of methyl parathion, with the detection limit of up to 002 μg / ml. Currently, more investigation is the chemiluminescence and immunoassay, molecular blotting, microfluidic microarray and other technologies to detect pesticide and veterinary drug residues in food [ 7], but still in the laboratory stage. 7], but still in the laboratory stage, the practical use is still rare. Chemiluminescence technology has the advantages of high sensitivity, fast reaction speed, good selectivity, simple instrumentation, etc., more suitable for field monitoring work. 3 Immunoassay techniques The immunoassay techniques used in pesticide residue analysis mainly include radioimmunoassay (RIA) and enzyme immunoassay (EIA). Due to the limitations of RIA in terms of instrumentation requirements, EIA has become one of the most widely used techniques in pesticide residue analysis, and EIA has been used in direct method, indirect method, antibody sandwich method, competition method, inhibition method, etc. The immunoassay is based on the antigen, the antibody, the antibody, the antibody, the antibody, the antibody, the antibody, the antibody, the antibody and the antibody. Immunoassay is a detection method based on antigen-antibody specific recognition and binding reaction. Organophosphorus pesticides are small molecular weight pesticides (MW%26lt;2500), to pesticide small molecules in the form of semi-antigens through a certain length of carbon chain connecting molecules and molecular weight of the carrier (generally proteins) to *** valence bond phase coupling to prepare artificial antigens to artificial antigens immunized animals to produce antibodies specific to the pesticide response (polyclonal antibodies), the use of hybridoma technology to prepare Antibodies with single antigen specificity (monoclonal antibodies) were prepared by hybridoma technique.M A Kumar [8] et al. used a combination of enzyme-linked immunoprobe technique and flow injection technique for detection of methyl parathion in the environment and food, which had high sensitivity and good specificity. In 1999, Liu Shuzhao [9] and others developed a linear concentration range of 10-1~10-4μg/ml, and the detection limit was lower than 001ng/ml. Wang Gangyi [10] and others synthesized an artificial antigen for methyl parathion and established an ELISA method, and the detection limit was 5ng/ml. At present, immunoassay technology is mainly used to detect pesticide and veterinary drug residues in food and environment. It is reported that hundreds of pesticides have established ELISA detection methods, such as carbendazim, carbofuran, parathion, parathion-methyl, etc. The detection limits of some organophosphorus pesticides can be as high as 1 ng/ml. The detection limit of certain organophosphorus pesticides can reach ng or even pg level, and some kits have been commercialized and widely used for rapid monitoring of field samples and large number of samples [11, 12]. So far due to its strong specificity, 1 kit can only detect a single organophosphorus pesticides can not detect pesticide multi-residue, and there is a certain degree of cross for structurally similar compounds, coupled with the difficulty of antibody preparation, the high cost of the kit, which limits its widespread use in pesticide residue detection. 4 Biosensor Technology A biosensor is usually a probing tool that is a tightly coordinated combination of a biosensitive component and a transducer with a selective and reversible response to a specific type of compound or biologically active substance [13-16]. When the substance to be measured and the molecular recognition element (composed of biological efficacy substances with recognition ability, such as enzymes, microorganisms, antigens and antibodies, etc.) are specifically combined, the resulting light, heat, etc. are transformed into electrical signals, optical signals, etc. that can be output by signal converters, and then processed electronically by the detector, and displayed or recorded on the instrument, so as to achieve the analytical detection purpose. 41 Enzyme biosensor Organophosphorus pesticides and acetylcholinesterase ester group of the active site of the irreversible bonding to inhibit the enzyme activity, the enzyme reaction generated by the pH value changes detected by the potentiometric biosensor. The advantages are fast, accurate and reusable, but the enzymes are highly substrate specific and less stable.Bernabeil M coupled several enzymatic reactions on a single biosensor thereby increasing the number of substrates to be measured, i.e., using a dual enzyme system of acetylcholinesterase and choline oxidase, a galvanic H2O2 sensor for the detection of pesticide pesticides pesticides pesticide pesticide pesticide pesticide paraoxon and aldicarb was prepared. 42 Immunobiosensors Biosensors that utilize immunochemical reactions between antibodies and antigens. It can detect pesticide residues in samples with high sensitivity, high selectivity, convenience and rapidity.Wan [17] et al. developed a portable fiber-optic immunosensor for the detection of methyl parathion with a minimum detection limit of 01 ng/ml.The fiber-optic immuno-biosensor developed by Anis et al. was used for the determination of parathion in samples and compared with chromatography, the method was simple and rapid, and the analysis cycle was shortened by 4/5. 43 Microbial sensors The microbial sensors were prepared using the immunochemical reaction between antibody and antigen. /43 Microbial Sensors The metabolic efficacy of living microorganisms is utilized to detect pollutants, one type is to use the respiratory efficacy of microorganisms that consume oxygen when assimilating substrates; the other type is to use different microorganisms containing different enzymes as enzyme sources. Mulchandani et al. transferred a plasmid carrying a fragment of the organophosphorus hydrolase (OPH) gene into a Moraxella catarrhalis bacterium and screened for improved bacteria that could express OPH extracellularly, resulting in sensors that could be prepared with detection limits as low as l×10-6mol/L and 2×10-7mol/L for methyl parathion and paraoxon. 10-7mol/L [18]. Biosensors have been widely used in environmental monitoring, food, medicine and other fields. In the detection of organic phosphorus and other analytical techniques, biosensors have the advantages of small size, low cost, high selectivity and anti-interference ability, fast response, etc., and can also detect multiple samples at the same time with high sensitivity. However, the current biosensor technology also exists in poor stability, short service life and other new problems. < 5 Prospects Current pesticide residue detection: light-emitting bacteria technology is mainly used in water quality testing and environmental planning, with the development of technology light-emitting bacteria method will be combined with electronic technology and optoelectronic technology, and gradually developed for the on-line monitoring system for organophosphorus pesticides on-site monitoring to provide a more rapid means of detecting analysis. Chemiluminescence is a highly sensitive trace and trace organophosphorus residue detection analysis technology developed in recent years, the future in the improvement and soundness of the original light-emitting reagents and systems at the same time, the synthesis of new light-emitting reagents and other technologies (eg, microfluidic chip technology, sensor technology, etc.) associated with more chemiluminescence analysis technology shows the advantages of rapid, sensitive and simple. ELISA technology and biosensor technology is still in its infancy. ELISA technology and biosensor technology are still in the initial stage, with the continuous improvement of analytical technology, ELISA to reduce the occurrence of cross-reactivity, to further improve the sensitivity and stability of the immune reagent kits continue to be commercialized; biosensors of multi-functionality (1 sensor can detect a variety of pesticide residues), reduce product costs, improve sensitivity, stability and prolong the life of the pesticide residues in the detection field they will get Further use and promotion, so that the use of rapid detection of pesticide residues in China's rapid detection of pesticide residues in the use of diversified situations. References 〔1〕 Thomtdka KW.Use of bioluminescent bacterium photobacterium phosphoreum to detect potentially biohazardous materials in water〔J〕. Environ Contam Toxicol, 1993,51(4):538. [2] Yuan Dongxing, Deng Yongzhi, Lin Yuhui. 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