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Wei Sheng Yan Jiu = Journal of Hygiene... May 2022A method for the rapid determination of dichlorvos, trichlorfon, fenthion, fenthion-sulfone, fenthion-sulfoxide, fenthion-oxon, fenthion-oxon-sulfone,...
[Determination of organophosphorus pesticide residues in milk of cows and sheep by ultra-high-performance liquid chromatography- tandem mass spectrometry combined with passing type purification method].
OBJECTIVE
A method for the rapid determination of dichlorvos, trichlorfon, fenthion, fenthion-sulfone, fenthion-sulfoxide, fenthion-oxon, fenthion-oxon-sulfone, fenthion-oxon-sulfoxide, phoxim, propetamphos, malathion, diazinon and coumaphos 13 common organophosphorus pesticides and their metabolites poison residues in milk of cows and sheep by ultra-high-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) with passing type solid phase extraction(SPE) purification was developed.
METHODS
After centrifugation at 4 ℃, the milk was purified by passing type SPE with acetonitrile precipitating protein and determined by UPLC-MS/MS in electrospray positive ion mode(ESI+) and multi-reaction monitoring scanning(MRM), external standard method for quantitative analysis with matrix matching standard curve.
RESULTS
The recoveries of 13 target compounds were between 81.5% and 107.5% and relative standard deviation was between 1.24% and 6.23% at three spiked levels of 5, 10, 20 μg/L. The detection limits of 13 target compounds were between 0.015 and 0.15 μg/L, and the quantitative limits were between 0.05 and 0.50 μg/L. No organophosphorus pesticide residues were detected in 20 samples of cows and sheep milk.
CONCLUSION
The method has the advantages of good linear independence, low detection limit, high precision and accuracy, and can be used for daily monitoring of milk and related products.
Topics: Animals; Cattle; Chromatography, High Pressure Liquid; Chromatography, Liquid; Female; Fenthion; Milk; Organophosphorus Compounds; Pesticide Residues; Pesticides; Sheep; Solid Phase Extraction; Sulfones; Sulfoxides; Tandem Mass Spectrometry
PubMed: 35718915
DOI: 10.19813/j.cnki.weishengyanjiu.2022.03.023 -
The Science of the Total Environment Sep 2022Organothiophosphate pesticides (OPPs) are the most commonly used pesticides, and their environmental migration brings serious water pollution and significant danger to...
Organothiophosphate pesticides (OPPs) are the most commonly used pesticides, and their environmental migration brings serious water pollution and significant danger to human health, and thus it is urgent to develop effective technologies for removal of OPPs from water. Herein, magnetic covalent organic framework (COF) with a triazine skeleton was fabricated for enhanced adsorption and removal of OPPs from water. Magnetic COF has a fluffy ball-like structure, high crystallinity, large BET surface area (1543 m g), and regular mesopores (~3.1 nm). Therefore, it displayed high adsorption rates and large adsorption capacities for four typical OPPs, pyridafenthion, phoxim, pyrimitate, and phorate. Based on adsorption kinetic and isotherms investigations, the batch experimental data of magnetic COF was effectively modeled by pseudo-second-order kinetics and the Freundlich isothermal model. The equilibrium adsorption capacities of magnetic COF composite for OPPs ranged from 163.9 to 178.6 mg g, which were about 10 times higher than the amorphous magnetic composite. The adsorption mechanism was further explored to verify the contributions of π-π, CH⋯π, and CH⋯S interactions to the adsorption of OPPs on the crystalline magnetic COF. Furthermore, the high removal rate of OPPs from the environmental water and reusability further indicated its potential in real applications as an effective adsorption material.
Topics: Adsorption; Humans; Magnetic Phenomena; Metal-Organic Frameworks; Organothiophosphates; Pesticides; Water
PubMed: 35688246
DOI: 10.1016/j.scitotenv.2022.156529 -
Journal of Agricultural and Food... May 2022The diamondback moth, (L.), has evolved with varying degrees of resistance to almost all major classes of insecticides and has become the most resistant pest worldwide....
The diamondback moth, (L.), has evolved with varying degrees of resistance to almost all major classes of insecticides and has become the most resistant pest worldwide. The multiresistance to different types of insecticides has been frequently reported in , but little is known about the mechanism. In this study, a carboxylesterase (CarE) gene, , was found significantly overexpressed in a field-evolved multiresistant population and can be dramatically induced by eight of nine tested insecticides. Results of the real-time quantitative polymerase chain reaction (RT-qPCR) showed that was predominantly expressed in the midgut and malpighian tubule of larvae. Knockdown of dramatically increased the susceptibility of the larvae to β-cypermethrin, bifenthrin, chlorpyrifos, fenvalerate, malathion, and phoxim, while overexpression of in increased the tolerance of the fruit flies to these insecticides obviously. More importantly, gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay showed that the recombinant PxαE14 expressed in exhibited metabolic activity against the six insecticides. The homology modeling, molecular docking, and molecular dynamics simulation analyses showed that these six insecticides could stably bind to PxαE14. Taken together, these results demonstrate that constitutive and inductive overexpression of contributes to detoxification of multiple insecticides involved in multiresistance in . Our findings provide evidence for understanding the molecular mechanisms underlying the multiresistance in insect pests.
Topics: Animals; Chromatography, Liquid; Drosophila melanogaster; Insecticide Resistance; Insecticides; Larva; Molecular Docking Simulation; Moths; Tandem Mass Spectrometry
PubMed: 35510781
DOI: 10.1021/acs.jafc.2c01867 -
Analytica Chimica Acta May 2022In this work, we reported the first use of a novel fluorescent probe for phoxim detection based on yellowish-green emissive carbon quantum dots (CQDs). By facile one-pot...
In this work, we reported the first use of a novel fluorescent probe for phoxim detection based on yellowish-green emissive carbon quantum dots (CQDs). By facile one-pot hydrothermal treatment of citric acid and p-phenylenediamine, the CQDs with yellowish-green luminescence were synthesized. The sensing mechanism is based on the quenching effect of phoxim on the fluorescence emission of CQDs by inner filter effect (IFE). The CQDs showed a good sensitivity and selectivity to phoxim detection and dual good linear relationships were provided in the concentration ranges of 1-10 μM and 10-98 μM, associated with the limit of detection of 0.09 μM. The proposed assay has been allowed to detect phoxim in real samples with satisfying recoveries ranging from 93 to 105.9%. Furthermore, due to the low cytotoxicity and excellent biocompatibility, the as-prepared CQDs was successfully used for cell imaging, demonstrating the considerable potential applications of such CQDs in biological field.
Topics: Carbon; Fluorescent Dyes; Organothiophosphorus Compounds; Quantum Dots
PubMed: 35473876
DOI: 10.1016/j.aca.2021.338685 -
Archives of Insect Biochemistry and... Oct 2022The nuclear receptor (NRs) gene family functions as ligand-dependent transcription factors in a variety of animals, which participates in a variety of biological...
The nuclear receptor (NRs) gene family functions as ligand-dependent transcription factors in a variety of animals, which participates in a variety of biological processes, such as cell differentiation, metabolic regulation, reproduction, development, insect metamorphosis. In this study, a nuclear receptor HR96 gene in silkworm Bombyx mori (BmHR96) was identified, and the responses of BmHR96 gene to 20-hydroxyecdysone (20E), three insecticides, and two disinfectants were analyzed and its function in phoxim exposure was explored. Quantitative real-time polymerase chain reaction indicated that the expression of BmHR96 mRNA was the highest in ovary of 5th instar Day 3 silkworm larvae and in silk gland of the wandering stage. The expression patterns of BmHR96 gene in ovary, head, testis, and midgut of different stages were different. After injecting 20E into B. mori, the expression of BmHR96 mRNA had no significant difference compared with control. Three insecticides and two disinfectants were used to treat B. mori, respectively, and it was found that they had different influence patterns on the expression level of BmHR96. siRNA of BmHR96 was injected into silkworm larvae and the expression of BmHR96 was decreased significantly after injecting 72 h. After silencing of BmHR96, B. mori was fed with phoxim-treated leaves. The results showed that the mortality of B. mori after silencing of BmHR96 was significantly higher than the control. Our results indicated that HR96 plays an important role in regulating the stress response of phoxim.
Topics: Animals; Bombyx; Disinfectants; Insect Proteins; Insecticides; Larva; Organothiophosphorus Compounds; RNA, Messenger
PubMed: 35470488
DOI: 10.1002/arch.21910 -
Environmental Science and Pollution... Sep 2022Phoxim is one of the main organophosphorus pesticides used in agricultural production. However, little information is known about how it affects the aquatic microbial...
Phoxim is one of the main organophosphorus pesticides used in agricultural production. However, little information is known about how it affects the aquatic microbial community and the intestinal microbiota of fish. Herein, we utilized shotgun metagenomics and 16S rRNA gene sequencing to reveal the aquatic eco-risk of phoxim. Seven days of phoxim exposure significantly changed the composition of aquatic microbial community, obliterated the interactions between microorganisms, and thus reduced the complexity and stability of the microbial community. During long-time exposure (i.e., 14 days), most of the ecological functions were restored due to the redundancy of the microbial community. However, phoxim exposure promoted the dissemination of elfamycin resistance gene. The zebrafish gut microbial community also recovered from a temporary ecological disorder of aquatic microbiota, but phoxim continually affected zebrafish growth and swimming behavior. Overall, our results demonstrated that phoxim exposure significantly changed the structure and function of the microbial community and displayed a negative impact on freshwater ecosystems in a short exposure time.
Topics: Animals; Gastrointestinal Microbiome; Genes, rRNA; Metagenomics; Microbiota; Organophosphorus Compounds; Organothiophosphorus Compounds; Pesticides; RNA, Ribosomal, 16S; Zebrafish
PubMed: 35449330
DOI: 10.1007/s11356-022-20325-8 -
Environmental Science and Pollution... Aug 2022With continuous development of pesticide dosage forms, emulsifiable concentrates using large amounts of organic solvents are gradually obsoleted. Nanoemulsions with high...
With continuous development of pesticide dosage forms, emulsifiable concentrates using large amounts of organic solvents are gradually obsoleted. Nanoemulsions with high water content have been developed and the preparation processes also evolved, but these processes still exist some problems, such as poor controllability and high energy consumption. Microfluidic is a controllable nanoemulsion preparation system which mainly applied to pharmaceutical synthesis. In this study, the pesticide phoxim nanoemulsion was prepared by microfluidic technology. The optimized formulation of phoxim nanoemulsion was composed of Tween 80 and pesticide emulsifier 500 as surfactant, hexyl acetate as oil, and n-propanol as co-surfactant. Moreover, when the flow rates of water and oil in the microfluidic system were adjusted to 5 μL/min and 20 μL/min, phoxim nanoemulsion was obtained with a cloud point/boiling point of 109 °C, a particle size of 21.5 ± 0.8 nm and a potential value of - 18.7 ± 0.6 mV. Furthermore, the nanoemulsion had a rapid release effect in vitro which could be fitted by the Ritger-Peppas model. The feeding toxicity of the phoxim nanoemulsion was higher than that of commercial formulation while the contact killing effect was higher than that of the active ingredient. Therefore, pesticide dosage was reduced and the insecticidal effect was enhanced by using phoxim nanoemulsions. These results also confirm the potential of microfluidics as a green process to produce pesticide nanoemulsions.
Topics: Animals; Emulsions; Microfluidics; Organothiophosphorus Compounds; Particle Size; Pesticides; Spodoptera; Surface-Active Agents; Water
PubMed: 35394625
DOI: 10.1007/s11356-022-20001-x -
Zhongguo Zhong Yao Za Zhi = Zhongguo... Mar 2022The demand for Angelicae Sinensis Radix, the dry root of Angelica sinensis, has been increasing year by year. However, the continuous cropping obstacles, frequent...
The demand for Angelicae Sinensis Radix, the dry root of Angelica sinensis, has been increasing year by year. However, the continuous cropping obstacles, frequent occurrence of pests and diseases, overuse of chemical pesticides, excessive pesticide residues and other problems in Angelicae Sinensis Radix production have attracted much attention. In this paper, we summarized the common diseases and pests attacking Angelica sinensis as well as the detection methods and characteristics of pesticide residues in Angelicae Sinensis Radix from 2002 to 2021. Additionally, we compared the limit standards of pesticide residues in Angelicae Sinensis Radix in and out of China and put forward suggestions for the high-quality and green development of Angelicae Sinensis Radix industry conside-ring the existing problems. The pesticide residues in Angelicae Sinensis Radix have been changing from organochlorines to organophosphorus pesticides. In recent years, some organophosphorus pesticides such as phorate, phoxim, isofenphos-methyl, phorate-sulfoxide, fenamiphos, isocarbophos, omethoate, and triazophos in Angelicae Sinensis Radix have seriously exceeded the standards. The detection methods of pesticide residues has evolved from chromatography to high performance chromatography-mass spectrometry, gas chromatography-mass spectrometry(GC-MS), and liquid chromatography-mass spectrometry(LC-MS), and some new detection techniques such as immunoassay have also been applied. Pesticide residues have become a primary factor that restricting the development of Angelicae Sinensis Radix industry. Therefore, moderate application of pesticides, establishment of ecological planting system, and strict limit standards of pesticide residues are necessary to solve the pesticide residue problem.
Topics: Angelica sinensis; Chromatography, Liquid; Organophosphorus Compounds; Pesticide Residues; Pesticides
PubMed: 35347942
DOI: 10.19540/j.cnki.cjcmm.20211220.102 -
Food Chemistry Jul 2022A ratiometric electrochemical immunosensor, based on DNA tetrahedron nanostructure (DTNS), is introduced for vegetable phoxim determination. DTNS spontaneously adheres...
Ratiometric immunosensor with DNA tetrahedron nanostructure as high-performance carrier of reference signal and its applications in selective phoxim determination for vegetables.
A ratiometric electrochemical immunosensor, based on DNA tetrahedron nanostructure (DTNS), is introduced for vegetable phoxim determination. DTNS spontaneously adheres onto gold-nanoparticle-modified electrode and forms stable three-dimensional structure, providing plenty of binding sites to the built-in reference, methylene blue (MB). Monoclonal antibody (m-Ab) is vertically linked onto DTNS vertex, selectively responses antigenic phoxim, and promotes the target signal of I. Thus, a ratiometric indicator, I/I, is sensibly established with the target signal (I) and the reference signal (I). Modifications, mechanisms and advances of the proposed method are subsequently examined with morphological methods and electrochemical experiments. This method brings considerable advances in analytical behaviors. The ratiometric signal presents better performance than solo system in repeatability and long-time stability. As-fabricated sensor presents wide dynamic range as 0.1∼30 μg/L, and limit of detection is well defined as 0.003 μg/L (S/N = 3). Finally, this method is verified with real-vegetable-sample analysis, certified HPLC and recovery test.
Topics: Biosensing Techniques; DNA; Electrochemical Techniques; Gold; Immunoassay; Limit of Detection; Methylene Blue; Nanostructures; Organothiophosphorus Compounds; Vegetables
PubMed: 35182867
DOI: 10.1016/j.foodchem.2022.132445 -
Analytical Chemistry Feb 2022A novel high-throughput aptamer microarray fluorescent method based on thioflavin T (ThT) was established for the sensitive detection of phoxim, parathion,...
A novel high-throughput aptamer microarray fluorescent method based on thioflavin T (ThT) was established for the sensitive detection of phoxim, parathion, fensulfothion, and isocarbophos. In this work, the aptamers in binding buffer tended to have the antiparallel G-quadruplex structure, which can bind ThT and release its potential fluorescence signal. However, when the organophosphorus pesticides (OPs) were present, partial aptamers preferred to bind them, forcing the displacement of ThT from the G-quadruplex and resulting in the significant decrease in fluorescence signal. Under optimal experimental conditions (12T spacer, 300 nM aptamer, and 80 μM ThT), the OP aptamer microarray has low limits of detection of 25.4 ng/mL for phoxim, 12.0 ng/mL for parathion, 7.7 ng/mL for fensulfothion, and 9.9 ng/mL for isocarbophos. The accuracy and reliability of the method is further verified by testing the recovery rate of OPs spiked in two different complicated sample matrices (pears and radishes). It is worth mentioning that not only the developed aptamer microarray technology has low sensitivity and a broad spectrum, but it also allows for high-throughput and rapid analysis of a variety OPs, which overcomes some of the shortcomings of other OP detection methods.
Topics: Aptamers, Nucleotide; Biosensing Techniques; Fluorescent Dyes; Organophosphorus Compounds; Pesticides; Reproducibility of Results; Spectrometry, Fluorescence
PubMed: 35133802
DOI: 10.1021/acs.analchem.1c04650