On-site rapid detection of multiple pesticide residues in tea leaves by lateral flow immunoassay

The application of pesticides (mostly insecticides and fungicides) during the tea-planting process will undoubtedly increase the dietary risk associated with drinking tea. Thus, it is necessary to ascertain whether pesticide residues in tea products exceed the maximum residue limits. However, the complex matrices present in tea samples comprise a major challenge in the analytical detection of pesticide residues. In this study, nine types of lateral flow immunochromatographic strips (LFICSs) were developed to detect the pesticides of interest (fenpropathrin, chlorpyrifos, imidacloprid, thiamethoxam, acetamiprid, carbendazim, chlorothalonil, pyraclostrobin, and iprodione). To reduce the interference of tea substrates on the assay sensitivity, the pretreatment conditions for tea samples, including the extraction solvent, extraction time, and purification agent, were optimized for the simultaneous detection of these pesticides. The entire testing procedure (including pretreatment and detection) could be completed within 30 min. The detected results of authentic tea samples were confirmed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), which suggest that the LFICS coupled with sample rapid pretreatment can be used for on-site rapid screening of the target pesticide in tea products prior to their market release.

Application and Promotion of Non-pesticide Replacing High-toxic Pesticide Techniques and Its Benefit Analysis in Kunming City

[ Objective] The paper was to operate the application and promotion of non-pesticide replacing high-toxic pesticides techniques in Kunming City, and to analyze its benefit. [ Method ] Through application and promotion of frequency trembler grid lamps, sticking plate trapping technology, construction of treatment ponds for field waste vegetable leaves, standardized （accurate） cultivation techniques, cultivation techniques of disease-resistant varieties and diverse cultivation technologies, the promotion benefit of non-pesticide replacing high-toxic pesticides techniques was comprehensively investigated and evaluated. [ Result ] The appli- cation and promotion area of non-pesticide replacing high-toxic pesticides techniques in Kunming City during 2006 -2010 reached 94 667 hm2. The investigation on control efforts and quantitative analysis of cost/benefit showed that the beneficial result of application and promotion of non-pesticide replacing high-toxic pesticides techniques was higher than the direct benefit of application and promotion of traditional pesticide replacing techniques. This improvement innovated the traditional pesticide replacing method in replacement work of high-toxic pesticides, reducing the usage volume of pesticide in Kunming City. [ Conclusion] The application and promotion of non-pesticide replacing high-toxic pesticides techniques improved the economic, social and ecological benefit of replacement work of high-toxic pesticides, protected the agricultural ecological environment and promoted the sustainable development of agricultural production.

Computational interaction analysis of organophosphorus pesticides with different metabolic proteins in humans

Pesticides have the potential to leave harmful effects on humans, animals, other living organisms, and the environment. Several human metabolic proteins inhibited after exposure to organophosphorus pesticides absorbed through the skin, inhalation, eyes and oral mucosa, are most important targets for this interaction study. The crystal structure of five different proteins, PDBIDs： 3LII, 3NXU, 4GTU, 2XJ1 and 1YXA in Homo sapiens （H. sapiens）, interact with organophosphorus pesticides at the molecular level. The 3-D structures were found to be of good quality and validated through PROCHECK, ERRAT and ProSA servers. The results show that the binding energy is maximum -45.21 relative units of cytochrome P450 protein with phosmet pesticide. In terms of H-bonding, methyl parathion and parathion with acetylcholinesterase protein, parathion, methylparathion and phosmet with protein kinase C show the highest interaction. We conclude that these organophosphorus pesticides are more toxic and inhibit enzymatic activity by interrupting the metabolic pathways in H. sapiens.

Statistical Analysis on Field Efficacy Trial of Pesticide Using Visual Basic

[Objective] To introduce a convenient and easy way for the statistical anal- ysis on field efficacy trials of pesticide by using Visual Basic. [Method] The calcula- tion procedure of using Visual Basic to conduct statistical analysis on the field efficacy of pesticides was introduced, and an example was used to illustrate the usage and skill of the program. [Result] The procedure could quickly and accurately con- duct statistical analysis on the field efficacy of pesticide by only inputting initial data of the test, and it could compare the significance of differences between various fac- tors. Its calculated results were consistent with the results of the specialized statisti- cal software DPS. [Conclusion] It is a quick and simple method with high accuracy and reliability, which can greatly improve the efficiency of pesticide formulation opti- mization.

Rules of Pesticide Use for Food Crop Diseases and Pests: A Concise Diagram Based on Correspondence Analysis

In order to ensure food security, the selection of pesticide must take into account the controlling effect and economy in the chemical control of food crop diseases and pests. Although China has registered a large number of pesticides and fungicides on food crops, traditional statistical methods cannot treat the complex relationships between crops, pests and diseases, as well as pesticides. To this end, the correspondence analysis was used to mine the data of pesticides being registered after January 1, 2010 for the prevention and control of pests and diseases on wheat, corn, and rice in China, in order to reveal the general rules of pesticide use for the prevention and control of grain crop pests and diseases and to provide scientifically recommended pesticide regimens.(1) Recommended pesticides for wheat diseases and pests: For underground pest control, phoxim, diazinon or clothianidin is recommended;imidacloprid is recommended for aphid control;avermectin is recommended for mite control;chlorpyrifos is recommended for midge control;the pesticides for rust control could be selected according to the order of epoxiconazole>flutriafol>kresoxim-methyl>cyproconazole≈hexaconazole;tebuconazole is recommended for the prevention and control of smut;difenoconazole is recommended for the simultaneous occurrence of take-all, smut and sheath blight;it is recommended to use carbendazim or thiophanate-methyl for the control of scab;and triazolone or pyraclostrobin is recommended for the control of powdery mildew.(2) Recommended pesticides for corn diseases and pests: For the control of underground pests, fipronil, carbosulfan or chlorpyrifos are recommended;thiamethoxam is recommended for control of planthoppers and corn aphids;Bacillus thuringiensis or phoxim is recommended for control of corn borers;pyraclostrobin is recommended for the control of northern leaf blight;tebuconazole is recommended for the control of head smut;and fludioxonil+metalaxyl-M is recommended for the control of corn stalk rot.(3) Recommended pesticides for rice diseases and pests: It is recommended to use triazophos, avermectin analogs or methoxyfenozide for the control of borers;for rice planthoppers, the pesticides could be selected in order of pymetrozine>imidacloprid>thiamethoxam>thiazide>nitenpyram;avermectin analogs are recommended for the control of rice leaf rollers;tebuconazole is recommended for the control of rice false smut;prochloraz and its manganese salts are recommended for the control of bakanae disease;hymexazol is recommended for the control of wilt disease;thifluzamide or hexaconazole is recommended for the control of sheath blight;and the pesticides for the control of rice blast are in order of tricyclazole>kasugamycin>fenoxanil>isoprothiolane>Bacillus subtilis. In addition, potential applications of correspondence analysis in other fields of plant protection are discussed.

Application of Laboratory Information Management System in Tea Pesticide Analysis Laboratory

The aim of this paper is to establish LIMS （laboratory information management system） for the tea pesticides analysis accredited laboratories in Taiwan. The LIMS could help Tungting station and Nantou pesticide inspection station to computerize the pesticide analysis data. It has completed eight management subsystems so far, including the basic information management subsystem, thesample processing management subsystem, the analysis data management subsystem, the analysis report management subsystem, the inspection standard management subsystem, the instrument connection management subsystem, the laboratory personnel training management subsystem and the laboratory quality document management subsystem. Using the automatic tea pesticide analysis information management system could help laboratory operations to reduce the amount of excess paperwork and human resource, which could ensure the analysis data quality is traceable and reliable.

Application of Mass Spectrometry (MS)-coupled Techniques in Pesticide Residue Detection

Pesticide residue detection is an important work to ensure the quality safety of agricultural products.In the process of agricultural production,in order to prevent and control agricultural diseases and pests,a certain amount of pesticides need to be used.However,if pesticides are used excessively,there will be certain pesticide residues in crops and related products.Therefore,it is necessary to do a good job in pesticide residue detection.The gas chromatography-mass spectrometry(GC-MS)and liquid chromatography-mass spectrometry(LC-MS)detection methods have good results and can effectively detect pesticide residues in related products.This paper reviewed and analyzed the application of GC-MS and LC-MS in pesticide residue detection,and proposed optimization measures based on practical experience,hoping to provide reference for relevant scholars.

Simultaneous Screening of 733 Pesticide Residues in Fruits and Vegetables by a GC/LC-Q-TOFMS Combination Technique

In this paper,we report the construction of two accurate mass databases and the development of a combination detection method that simultaneously screens for 733 pesticide and chemical contaminant multi-residues via high-throughput liquid chromatography(LC)-and gas chromatography(GC)-quadru pole-time-of-flight mass spectrometry(Q-TOFMS).This work demonstrates that electronic mass spectral standards may replace chemical-source standard materials as references through one sample preparation and the combination of GC/LC-Q-TOFMS screening.This cutting-edge technique has also replaced multiresidue determination using targeted detection with non-targeted screening.The pesticide residue types,sensitivity,recovery,and reproducibility of this combination technique are evaluated in eight fruit and vegetable matrices.This technique shows three advantages:①In comparison with the discovery capability of a single technique,the combination technique shows an improvement of 51.1%(GC-QTOFMS)and 39.6%(LC-Q-TOFMS),respectively;②the combination technique can satisfy a screening limit lower than 10μg·kg^-1 and meet the requirements of“uniform standards,”although some of the pesticide residues could be optimized to further improve screening sensitivity;③over 488 pesticides with recoveries between 60%-120%and relative standard deviation(RSD)<20%at a spiked level of 10μg·kg^-1 were detected with the combination technique in eight different matrices.From 2012 to 2017,this combination technique was applied in an investigation to screen pesticide residues from 1384 sampling locations for 38138 batched samples covering 18 categories and 134 types of fruits and vegetables obtained from across the mainland of China.After statistical analysis,533 pesticides in 115891 determinations were detected,and the regularity of pesticides in the fruits and vegetables sold on the Chinese market was shown.

A novel thermal biosensor based on enzyme reaction for pesticides measurement

A novel thermal biosensor based on enzyme reaction for pesticides detection has been developed. This biosensor is a flow injection analysis system and consists of two channels with enzyme reaction column and identical reference column, which is set for eliminating the unspecific heat. The enzyme reaction takes place in the enzyme reaction column at a constant temperature(40℃) realized by a thermoelectric thermostat. Thermosensor based on the thermoelectric module containing 127 serial BiTe-thermocouples is used to monitor the temperature difference between two effluents from enzyme reaction column and reference column. The ability of this biosensor to detect pesticides is demonstrated by the decreased degree of the hydrolytic heat in two types of thermosensor mode. The hydrolytic reaction is inhibited by 36% at 1 mg/L DDVP and 50 % at 10 mg/L DDVP when cell-typed thermosensor is used. The percent inhibition is 30% at 1 mg/L DDVP and 42% at 10 mg/L DDVP in tube-typed thermosensor mode. The detection for real sample shows that this biosensor can be used for detection of organophosphate pesticides residue.

Multiresidue Method for Determination of 67 Pesticides in Water Samples Using Solid-Phase Extraction with Centrifugation and Gas Chromatography-Mass Spectrometry

A new multi-residue method based on solid-phase extraction (SPE) with centrifugation was developed for determination and quantitation of 67 pesticides in water samples. Two SPE cartridges were tested: Chromabond C18 and Oasis HLB. Parameters that influence the extraction efficiency such as the eluent volume, the sample loading volume, the addition of organic solvent to water sample, sorbent drying and elute concentration were optimized. The innovation of this work was the examination of the use of a centrifugation technique in both the drying and elution steps. When combined with centrifugation, the volume of the elution solvent was reduced to 2 mL and the time for sorbent drying decreased also to 10 min under vacuum. Under the optimized conditions, this method showed good recoveries higher than 65% - 68% for the 67 analyzed pesticides using the C18 and HLB cartridges with relative standard deviations lower than 9.7% - 12.3%. Limits of quantification were between 2 and 20 ng.L–1. The simplicity of the described method, use of less of organic solvent, short procedure time, and good recoveries demonstrate the advantages of this environmentally friendly approach for routine analysis of numerous samples.

DNA Damage Caused By Pesticide-contaminated Soil

Objective To determine the DNA damaging potential and the genotoxicity of individual compounds in pesticide contaminated soil. Methods In the present study, DNA damaging potential of pesticide-contaminated soil and the genotoxicity of individual compounds present in the soil were assessed using fluofimetdc analysis of DNA unwinding assay. Results The contaminated soil sample showed 79% （P〈0.001） of DNA strand break, whereas technical grade of major catbaryl and α-naphthol constituents of the contaminated soil showed 64% （P〈0.01） and 60% （P〈0.02） damage respectively. Conclusion Our results indicate that the toxicity caused by contaminated soil is mainly due to carbatyl and α -napthol, which are the major constituents of the soil sample analyzed by CrC-MS.

Role of penehyclidine in acute organophosphorus pesticide poisoning

BACKGROUND:Penehyclidine is a newly developed anticholinergic agent.We aimed to investigate the role of penehyclidine in acute organophosphorus pesticide poisoning(OP)patients.METHODS:We searched the Pubmed,Cochrane library,EMBASE,Chinese National Knowledge Infrastructure(CNKI),Chinese Biomedical literature(CBM)and Wanfang databases.Randomized controlled trials(RCTs)recruiting acute OP patients were identifi ed for meta-analysis.Main outcomes included cure rate,mortality rate,time to atropinization,time to 60%normal acetylcholinesterase(AchE)level,rate of intermediate syndrome(IMS)and rate of adverse drug reactions(ADR).RESULTS:Sixteen RCTs involving 1,334 patients were identifi ed.Compared with the atropineor penehyclidine-alone groups,atropine combined with penehyclidine significantly increased the cure rate(penehyclidine+atropine vs.atropine,0.97 vs.0.86,RR 1.13,95%CI[1.07–1.19];penehyclidine+atropine vs.penehyclidine,0.93 vs.0.80,RR 1.08,95%CI[1.01–1.15])and reduced the mortality rate(penehyclidine+atropine vs.atropine,0.015 vs.0.11,RR 0.17,95%CI[0.06–0.49];penehyclidine+atropine vs.penehyclidine,0.13 vs.0.08,RR 0.23,95%CI[0.04–1.28]).Atropine combined with penehyclidine in OP patients also helped reduce the time to atropinization and AchE recovery,the rate of IMS and the rate of ADR.Compared with a single dose of atropine,a single dose of penehyclidine also signifi cantly elevated the cure rate,reduced times to atropinization,AchE recovery,and rate of IMS.CONCLUSION:Atropine combined with penehyclidine benefi ts OP patients by enhancing the cure rate,mortality rate,time to atropinization,AchE recovery,IMS rate,total ADR and duration of hospitalization.Penehyclidine combined with atropine is likely a better initial therapy for OP patients than atropine alone.

Health Risk Assessment on Pesticide Residues in Drinking Water in Shenzhen

Objectives: To conduct health risk assessment of drinking water pesticide residues and its annual trend analysis in Shenzhen City. Methods: The samples of product water, pipe water and secondary supply water from 2011 to 2013 were collected and analyzed. The evaluation models of health risk assessments for children and adults on the 12 non-carcinogenic materials (namely heptachlor, pentachlorophenol, hexachlorocyclohexane, hexachlorobenzene, DDT, malathion, glyphosate, dimethoate, bentazone, atrazine, chlorothalonil, furadan) were recommended by the U.S. Environmental Protection Agency (US EPA). Results: The results showed that the maximums of the measured indicators in the above were controlled in accordance with the National Health Standards (GB5749-2006) published by Ministry of Health in China. The adults and children’s health indices (HIs) of the 12 non-carcinogenic materials were greater than 1 (2.323 - 6.312). Dimethoate residue in factory and peripheral water was the largest risks of harm among the non-carcinogenic pollutants measured. And its HIi (Its Hli) was also greater than 1 (1.995 - 5.094) and followed by hexachlorobenzene and heptachlor. Annual rising trend on health risk of the 12 pesticide residues indicated that their HIT on adults was 2323. 18 × 10-3 in 2011, 2340. 18 × 10-3 in 2012 and 2431. 97 × 10-3 in 2013, and HIT on children was 2965. 07 × 10-3 in 2011, 2986. 77 × 10-3 in 2012 and 3103. 93 × 10-3 in 2013, respectively. This study also suggested that the average risk of peripheral water samples (HIT was equal to 2619. 64 × 10-3) was greater than the factory samples’ (HIT was the same as 2366. 92 × 10-3), and the children’s health risk was greater than the adults’. Conclusions: Health risks of drinking water pesticide residues in Shenzhen have exceeded the threshold values. The dimethoate was the main hazard and had been rising annually, and the children’s health risk was greater than the adults’.

Developments in Analytical Methods for Detection of Pesticides in Environmental Samples

The present review gives a survey of all the published methods along with their advantages and limitations. Traditional methods like thin layer chromatography, gas chromatography, liquid chromatography etc are still in use for this purpose. But some recent bio-analytical methods such as immunosensors, cell based sensors etc. have also gained equal importance. This article also overviews various electro-analytical methods and their applications as detection devices when combined with FIA and biosensors. Lastly nanoparticle based biosensors have also been discussed. The review concludes with futuristic approach to reduce the risks caused by pesticides. This scrutiny should provide concise evaluation of different techniques employed for pesticide detection in environmental samples.

Industrialization Process of Pesticide Residue Grade n-Hexane

This project is funded by the China government to develop the industrialization process of pesticide residue grade n-hexane, in which the industrial n-Hexane is used as crude purified by decoloration, distillation and filtration process. The products are validated by National Research Center for Environmental Analysis and Measurement (CNEAC), National Research Center for Geoanalysis, Chinese Academy of Inspection and Quarantine (CAIQ), Chinese Academy of Agricultural Sciences (CAAS) and other government originations for polychlorinated biphenyls, organochlorine pesticide or chiral pesticides analysis and further confirmed that it’s competitive to all others imported n-Hexane currently occupied in China. This patented technique will meet pesticide residue grade n-Hexane market in China and seek for cooperation globally.

Research on Pesticide Residues of Cypermethrin in Lettuce

In order to find the effective method to reduce pesticide residues in vegetables, and promote the healthy development of vegetable industry. The paper used chlorothalonil, fenvalerate, dimethoate widely used pesticides as experimental material, using GC method to measure residual dynamics of vegetable pesticide. The results show that： fenvalerate, dimethoate, chlorothalonil pesticide residues in lettuce was higher than that tomato in the application day, respectively reach at 42.9%, 44.9%, 57.8%, pesticide degradation rate in open land were significantly higher than those in greenhouse within 5-20 days. The test showed that： the degradation of pesticide amount is in 8.77%r-19.64% within 1 days. The initial concentration of pesticides on vegetables are relevant with surface area of vegetable edible parts; the degradation speed of pesticide degradation rate in greenhouse vegetable is obviously slower than the open field vegetable; pesticide deposition phenomenon is an important factor affecting the pesticide residues in greenhouse.

Determination of Organochlorine and Synthetic Pyrethroid Pesticide Residues in Water Samples Collected from Different Locations of Bangladesh

The present study was aimed to validate an analytical method for the quantification of 19 organochlorine and 2 synthetic pyrethroid pesticide residues in water samples using modified quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction and Gas Chromatography coupled with Electron Capture Detector (ECD). The selected pesticide residues were determined by in-house validated method. The analytical method was validated by evaluating the accuracy, precision, linearity, limit of detection (LOD) and limit of quantification (LOQ). The average recoveries of the selected pesticides ranged from 78% to 117% with RSDr ≤ 12% in two fortification levels of 0.02 and 0.1 mg/L. The linearity was ≥0.995 for all of the selected pesticides. The LOD ranged from 0.003 to 0.006 mg/L and the LOQ was 0.02 mg/L for all the selected analytes. This method was applied satisfactorily for the residue analysis of 108 water samples collected from nine districts of Bangladesh. Among the analyzed samples, only 4 had cypermethrin residues (0.026 mg/L, 0.034 mg/L, 0.045 mg/L and 0.05 mg/L). The level of detected cypermethrin residues were above the WHO recommended guide line values of water quality.

植物生长调节剂在花生中的应用及安全性分析

为明确花生生产中植物生长调节剂的使用情况,通过查询中国农药信息网,统计汇总花生目前有效登记调节剂种类,并查询食品安全国家标准《食品中农药最大残留限量》(GB 2763—2021)中花生中调节剂的最大残留限量和检测方法,分析花生生产中主要使用的调节剂的毒性,为下一步相关标准的制定和修订提出意见和建议,同时也为花生产业的出口创汇及高质量发展提供参考,提升中国花生产业的国际竞争力,保障中国花生产业健康可持续发展。

高粱、谷子两种谷物类杂粮用农药登记现状及分析

本文通过检索中国农药信息网数据,对登记作物为高粱和谷子的农药进行梳理。总结分析了这两种作物农药登记产品数量、有效成分、毒性、防治对象、剂型等特点,找出两种作物农药登记存在的问题,并提出相应的建议。以期为高粱和谷子两种谷物类杂粮农药登记提供参考和方向。