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Analytical Chemistry May 2021Most of the fluorescence sensors require choline oxidase or quenchers to detect organophosphorus pesticides (OPs) based on a single hydrolysate and suffer from high...
Most of the fluorescence sensors require choline oxidase or quenchers to detect organophosphorus pesticides (OPs) based on a single hydrolysate and suffer from high cost, complex procedures, weak stability, and low sensitivity. Here, we proposed a brand-new fluorescence strategy for highly sensitive detection of OPs based on both hydrolysate-response disulfide bond-functionalized gold nanoclusters (S-S-AuNCs) without additional substances. S-S-AuNCs were synthesized via a facile one-step redox reaction and emitted bright red light with ultrasmall size and high water dispersion. Interestingly, S-S-AuNCs displayed a unique response to thiol compounds and low pH values and were thus pioneered as a high-efficiency sensor for OPs based on acetylcholinesterase (AChE)-catalyzed hydrolysis of acetylthiocholine into thiocholine and CHCOOH and OP inhibition of AChE activity. Further, S-S-AuNCs were employed to monitor the residue, distribution, and metabolization of methidathion in pakchoi with acceptable results. We believe that this work supplies a simpler and more highly sensitive approach for OP assay than the known ones and opens a new avenue to development of multistimulus-responsive and high-performance fluorescence substances.
Topics: Acetylcholinesterase; Biosensing Techniques; Disulfides; Gold; Hydrogen-Ion Concentration; Organophosphorus Compounds; Oxidation-Reduction; Pesticides
PubMed: 33961403
DOI: 10.1021/acs.analchem.1c01414 -
Analytical Biochemistry May 2021Intentional or unintentional intake of anticholinesterase pesticides became common due to their extensive use in agricultural and domestic purposes, resulting in...
Intentional or unintentional intake of anticholinesterase pesticides became common due to their extensive use in agricultural and domestic purposes, resulting in numerous poisoning cases. A simple, accurate, and sensitive gas chromatography-ion trap mass spectrometry-based method for the quantification of 12 anticholinesterase pesticides (monocrotophos, dimethoate, dichlorvos, azinphos-methyl, carbofuran, chlorpyrifos, dialifos, diazinon, malathion, parathion, methidathion, and terbufos) in serum was developed, and its utility in patients with alleged pesticides poisoning was assessed. The quantification was performed using liquid-liquid extraction by toluene/chloroform (4:1,v/v) with 500 μL of serum. On column limit of detection and limit of quantification were less than 50.00 μg/L. The recovery ranged from 97.54 to 103.23%. The calibration curves were linear (R > 0.9937). Accuracy was found to be between - 7.1 and 7.2%. Intra-day and inter-day reproducibility was less than 17% for the spiked quality control serum samples. The level of pesticide in serum quantified by the validated method correlated with clinical signs and symptoms, pseudo-cholinesterase activity, total atropine dose, length of hospital stay, and clinical outcome in 15 patients with alleged pesticide poisoning. The validated method may be used for monitoring and prognosis in patients with pesticide poisoning and diagnosis of poisoning in forensic toxicology.
Topics: Calibration; Cholinesterase Inhibitors; Gas Chromatography-Mass Spectrometry; Humans; Liquid-Liquid Extraction; Pesticides; Reproducibility of Results; Spectrometry, Mass, Electrospray Ionization
PubMed: 33705722
DOI: 10.1016/j.ab.2021.114158 -
Journal of Agricultural and Food... Mar 2021Development of simple, sensitive, and reliable fluorescence sensors for monitoring the residue, distribution, and variation of organophosphorus pesticides (OPs) in...
Development of simple, sensitive, and reliable fluorescence sensors for monitoring the residue, distribution, and variation of organophosphorus pesticides (OPs) in agricultural crops is highly urgent but remains challenging, which is ascribed to deprivation of an ideal fluorophore and ingenious detection strategy. Herein, we report the fabrication of cadmium telluride quantum dots (CdTe QDs) with bright emission, good water dispersion, and long emission wavelength for OP screening based on the unique response of CdTe QDs to pH and the inhibition of OPs on acetylcholinesterase (AChE) activity. AChE catalyzed hydrolysis of acetylcholine (ACh) into CHCOOH, which protonated CdTe QDs to decline the fluorescence, whereas target OP impeded AChE from catalyzing hydrolysis of ACh into CHCOOH, making little influence in fluorescence of CdTe QDs. On the basis of the change in fluorescence, sensitive detection of OP was acquired, with the limit of detection at 0.027 ng/mL, which was comparable or lower than that of most known OP sensors. Furthermore, the CdTe-QD-based sensor was successfully applied for precisely monitoring the residue, distribution, and variation of methidathion in Chinese cabbage and cultivated soil. Therefore, the proposed sensor was anticipated to supply a promising alternative for food safety guarantee and was an valuable application for OP screening.
Topics: Biosensing Techniques; Cadmium Compounds; Crops, Agricultural; Hydrogen-Ion Concentration; Organophosphorus Compounds; Pesticides; Quantum Dots; Spectrometry, Fluorescence; Tellurium
PubMed: 33635638
DOI: 10.1021/acs.jafc.0c08212 -
The Science of the Total Environment Mar 2021The buds and initial flowers of honeysuckle (Lonicera japonica Thunb.) are most widely used in traditional Chinese medicines (TCMs). In recent years, the problem of...
The buds and initial flowers of honeysuckle (Lonicera japonica Thunb.) are most widely used in traditional Chinese medicines (TCMs). In recent years, the problem of pesticide residues in honeysuckle has attracted much attention. This research aimed to study pesticide residual situation of honeysuckle in China and estimate the potential health risks for consumers using the HQ (hazard quotient) and HI (hazard index) methods. A reliable and robust method was established to determine and quantify 137 pesticide residues simultaneously by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) for 151 honeysuckle samples from different planting bases in China in 2017 and 2018. Fifty-four pesticides were detected in total, including 10 unauthorized pesticides (chlorpyrifos, fipronil, carbofuran, omethoate, isofenphos-methyl, triazophos, methomyl, dimethoate, methidathion, and methamidophos). One hundred and fifty (99.3%) samples contained at least 1 and up to 31 pesticides and/or their metabolites, with concentrations ranging from 0.001 to 3.087 mg/kg. Carbendazim, chlorbenzuron, imidacloprid, chlorpyrifos, and acetamiprid were the most frequently detected pesticides in 2017 and 2018, and the corresponding detection rates were 95.31%, 64.06%, 65.63%, 53.13%, 57.81%, and 98.85%, 88.51%, 70.11%, 77.01%, 57.47%, respectively. The acute hazard quotient (HQ) of carbofuran was 1.54 for specific population (fetus, infants, and pregnant or nursing women), which indicated that it posed a potential acute health risk. In the cumulative risk assessment, the acute hazard index (HI) of insecticides in honesuckle for children and the specific population were 1.34 and 3.36, respectively, suggesting that they posed potential acute cumulative health risks. These results were of theoretical and practical value for evaluating the safety of honeysuckle and improving its quality and safety.
Topics: Child; China; Food Contamination; Humans; Lonicera; Pesticide Residues; Risk Assessment; Tandem Mass Spectrometry
PubMed: 33121779
DOI: 10.1016/j.scitotenv.2020.142747 -
Pest Management Science Feb 2021Integrating fungal biocontrol agents into crop protection programs dominated by synthetic pesticides is an important first step towards developing an integrated pest...
BACKGROUND
Integrating fungal biocontrol agents into crop protection programs dominated by synthetic pesticides is an important first step towards developing an integrated pest management (IPM) program; however, their successful integration relies on an understanding of how their performance may be impacted by the remaining agrochemicals deployed for managing other pests and diseases. In this study we tested 10 formulated pesticides used in macadamia production at different concentrations to determine their effects on the germination, mycelial growth and sporulation of Metarhizium anisopliae and Beauveria bassiana in vitro. Further tests with laboratory-grade actives of the noncompatible pesticides were conducted to determine whether any antagonistic effects were caused by the active constituent or by formulation additives.
RESULTS
At their registered concentrations, formulated trichlorfon, acephate and indoxacarb were compatible with M. anisopliae, whereas B. bassiana showed compatibility with formulated trichlorfon, acephate, indoxacarb, sulfoxaflor and spinetoram. Bioassays using laboratory-grade active constituents indicated that the adverse impact of formulated beta-cyfluthrin on both fungal species and that of formulated methidathion on B. bassiana is probably due to components of the emulsifiable concentrate formulations rather than their active constituents. Diazinon was the only insecticidal active that showed high toxicity to both fungal species. The two fungicides, carbendazim and pyraclostrobin, were toxic to both fungal species at all tested concentrations.
CONCLUSION
Our results identify which pesticides used on macadamias in Australia are compatible and incompatible with entomopathogenic fungi. Future studies on pesticide degradation rates will help define the spray intervals required to eliminate these adverse effects.
Topics: Australia; Beauveria; Fungicides, Industrial; Insecticides; Macadamia; Metarhizium; Pest Control, Biological
PubMed: 32865346
DOI: 10.1002/ps.6065 -
Mikrochimica Acta Aug 2020A novel magnetic dual-template molecularly imprinted polymer (DMIP) was prepared with methyl-parathion and quinalphos as templates. For comparison, a series of...
Magnetic solid phase extraction sorbents using methyl-parathion and quinalphos dual-template imprinted polymers coupled with GC-MS for class-selective extraction of twelve organophosphorus pesticides.
A novel magnetic dual-template molecularly imprinted polymer (DMIP) was prepared with methyl-parathion and quinalphos as templates. For comparison, a series of single-template polymers with only methyl-parathion (MPMIP) or quinalphos (QPMIP) as template as well as a non-imprinted polymer (NIP) in the absence of the template, were synthesized using the same procedure of DMIP. The obtained MIPs were characterized by scanning electron microscopy(SEM), Fourier transform infrared (FT-IR) spectroscopy, vibrating sample magnetometer (VSM), and X-ray diffraction (XRD). The properties including kinetic effect, thermodynamic effect, selectivity, and reusability of MIPs were investigated . Only DMIP possessed high affinity and good recognition for all twelve OPPs including quinalphos, isazophos, chlorpyrifos-methyl, chlorpyrifos, methidathion, triazophos, profenofos, fenthion, fenitrothion, methyl-parathion, parathion, and paraoxon in comparison to MPMIP, QPMIP, or NIP. Moreover, DMIP was used as magnetic solid phase extraction (MSPE) sorbent for the pre-concentration of twelve OPPs in cabbage samples. The developed DMIP-MSPE-GC-MS method showed high sensitivity, low LODs (1.62-13.9 ng/g), fast adsorption equilibrium (10 min), and acceptable spiked recoveries (81.5-113.4%) with relative standard deviations (RSD) in the range 0.05-7.0% (n = 3). The calibration plots were linear in the range 10-800 ng/mL with coefficients of determination (R) better 0.99 for all twelve compounds. These results suggest that the DMIP is applicable for rapid determination and high throughput analysis of multi-pesticide residues. Graphical abstract.
Topics: Adsorption; Brassica; Food Contamination; Gas Chromatography-Mass Spectrometry; Limit of Detection; Magnetic Phenomena; Magnetite Nanoparticles; Methyl Parathion; Molecularly Imprinted Polymers; Organothiophosphorus Compounds; Pesticides; Solid Phase Extraction
PubMed: 32812169
DOI: 10.1007/s00604-020-04465-7 -
Chemosphere Dec 2020Organophosphorus insecticides are known to be partly transformed to their respective oxons during the chlorination step of drinking water treatment. For most...
Effect of chlorination on anti-acetylcholinesterase activity of organophosphorus insecticide solutions and contributions of the parent insecticides and their oxons to the activity.
Organophosphorus insecticides are known to be partly transformed to their respective oxons during the chlorination step of drinking water treatment. For most organophosphorus insecticides, the toxicological endpoint for determining acceptable daily intake levels is inhibition of acetylcholinesterase (AChE). Like the parent insecticides, oxons also inhibit AChE, so the presence of oxons in drinking water is also evaluated. However, no attention is paid to the possible presence of transformation products (TPs) other than oxons. In the present study, we determined whether the anti-AChE activity observed for chlorinated solutions of the organophosphorus insecticides malathion and methidathion could be solely attributed to the parent compounds and their oxons. Upon chlorination, both malathion and methidathion were immediately transformed to their oxons; the maximum transformation ratios were 60% and 30%, respectively, indicating that at least 40% and 70% of these compounds were transformed into other TPs. Before chlorination, malathion- and methidathion-containing solutions exhibited little to no anti-AChE activity, but the solutions showed strong activity after chlorination. The contributions of the parent insecticides and their oxons to the activities of the chlorinated samples were calculated from the concentrations of the compounds in the samples and dose-response curves for chemical standards of the compounds. For both the malathion-containing solution and the methidathion-containing solution, the calculated anti-AChE activities were almost the same as the observed activities at every chlorination time. This suggests that the observed activities could be attributed solely to the parent insecticides and their oxons, indicating that other TPs need not be considered.
Topics: Acetylcholinesterase; Animals; Cholinesterase Inhibitors; Halogenation; Insecticides; Malathion; Organophosphorus Compounds; Organothiophosphorus Compounds; Water Purification
PubMed: 32721694
DOI: 10.1016/j.chemosphere.2020.127743 -
Chemosphere Nov 2020Citrus is highly consumed in China and considered a major source of pesticide carrier in human diet. In this paper, pesticide residues in mandarins, tangerines and...
Citrus is highly consumed in China and considered a major source of pesticide carrier in human diet. In this paper, pesticide residues in mandarins, tangerines and oranges from China were evaluated, as well as the quality and long-term dietary risks for the Chinese consumers. Temporal variations for eight MRL non-compliant pesticides were also investigated. 106 pesticides were analyzed using QuEChERS procedure and UPLC-MS/MS, GC-MS and GC methods. Forty different pesticides were detected in 86% of the 2922 samples from 2013 to 2018. Chlorpyrifos was the most frequently detected pesticide with a detection rate of 40%. Residues of eight pesticides in 3.8% of the total samples exceeded their MRLs. The most severely excessive pesticide was bifenthrin with 283% MRL. The occurrences and exceeding rates of eight pesticides presented clear temporal variations during the six harvesting years. Isocarbophos, carbofuran and triazophos were the main risk factors threatening the citrus safety pre-2015, whereas profenofos and bifenthrin gradually became dominant after 2016, coinciding with government control measures. The index of quality for residues (IqR) levels of 88% of the samples were below 1.0, which indicated a satisfactory quality of citrus fruits in China, although 70% of the samples contained two or more residues. The cumulative chronic dietary risks were acceptable for both the Chinese general population and children and would not pose health risks. However, more strictly enforced control measures for methidathion and isocarbophos, and reduced usage of triazophos, quinalphos, profenofos and bifenthrin should be pursued to further improve the safety of citrus fruits.
Topics: Child; China; Chromatography, Liquid; Citrus; Dietary Exposure; Food Contamination; Fruit; Gas Chromatography-Mass Spectrometry; Humans; Pesticide Residues; Risk Assessment; Tandem Mass Spectrometry
PubMed: 32569958
DOI: 10.1016/j.chemosphere.2020.127381 -
International Journal of Environmental... May 2020Organochlorine (OCPs) and organophosphorus pesticides (OPPs) have been intensively applied in rice paddy field farming to control pest infestation and increase the...
Organochlorine (OCPs) and organophosphorus pesticides (OPPs) have been intensively applied in rice paddy field farming to control pest infestation and increase the yield. In this study, we investigated the presence of organochlorine and organophosphorus pesticides in paddy rice and soil from rice plantations in Thailand and China. According to concentration and distribution of OCPs, the most abundant OCPs residues in rice and soil from Thailand and China were dichlorodiphenyltrichloroethane and hexachlorocyclohexanes. The OPPs of methidathion, carbophenothion, chlorpyrifos, and diazinon were common to Thailand and China in both types of samples. The detection frequency of multiple types of these pesticides was greater than 50% of total samples. The relative concentration of some OPPs residues in rice and soil from Thailand and China were significantly different from each other (p < 0.0083), whereas, no significant difference was observed for the relative concentration of OCPs residues in rice and soil from both countries, except for HCHs (p < 0.05). Bioaccumulation factors of OCPs between rice and soil samples indicated that OCPs and OPPs in soil could accumulate in rice. The carcinogenic and non- carcinogenic risks of OCPs and OPPs seem to be in the safe range as recommended by the European Union.
Topics: China; Environmental Monitoring; Humans; Hydrocarbons, Chlorinated; Oryza; Pesticides; Risk Assessment; Soil; Soil Pollutants; Thailand
PubMed: 32471043
DOI: 10.3390/ijerph17113786 -
Soudni Lekarstvi 2019We present an autopsy case involving ingestion of methidathion, an organothiophosphate pesticide. A headspace gas chromatography mass spectrometry system was used for...
We present an autopsy case involving ingestion of methidathion, an organothiophosphate pesticide. A headspace gas chromatography mass spectrometry system was used for screening of volatile compounds. Subsequent toxicological analysis was performed using liquid chromatography tandem mass spectrometry. Xylene and ethylbenzene were detected in stomach contents. We also identified methidathion at concentrations of 3.07 and 2240 µg/ml in femoral venous blood and stomach contents, respectively. We concluded that the victim ingested methidathion insecticide, with an estimated dose of at least 9.2 g.
Topics: Autopsy; Gas Chromatography-Mass Spectrometry; Humans; Insecticides; Organothiophosphorus Compounds
PubMed: 31842549
DOI: No ID Found