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Journal of Chromatography. B,... Jun 2023Carbamate pesticides are extensively used in agriculture for their inhibition to acetylcholinesterase and damages to the insects' neural systems. Because of their...
A retrospective screening method for carbamate toxicant exposure based on butyrylcholinesterase adducts in human plasma with ultra-high performance liquid chromatography-tandem mass spectrometry.
Carbamate pesticides are extensively used in agriculture for their inhibition to acetylcholinesterase and damages to the insects' neural systems. Because of their toxicity, human poisoning incidents caused by carbamate pesticide exposure have occurred from time to time. What's more, some lethally toxic carbamate toxicants known as carbamate nerve agents (CMNAs) have been supplemented in Schedule 1 of the Annex on Chemicals in the Chemical Weapons Convention (CWC) by Organisation of the Prohibition of Chemical Weapons (OPCW) from 2020. And some other carbamates, like physostigmine, have been used in clinical treatment as anticholinergic drugs and their misuse may also cause damages to the body. Similar to organophosphorus toxicants, carbamate toxicants would react with butyrylcholinesterase (BChE) in plasma when entering the human body, resulting in the BChE adducts, based on which the exposure of carbamate toxicants could be detected retrospectively. In this study, methylcarbamyl nonapeptide and dimethylcarbamyl nonapeptide from pepsin digestion of BChE adducts were identified with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) in product ion scan mode. Carbofuran was chosen as the target to establish the detection method of carbamate toxicant exposure based on methylcarbamyl nonapeptide digested from methylcarbamyl BChE. Procainamide-gel affinity purification, pepsin digestion and UHPLC-MS/MS analysis in multiple reaction monitoring (MRM) mode were applied. Under the optimized conditions of sample preparation and UHPLC-MS/MS MRM analysis, the limits of detection (LODs) reached 10.0 ng/mL of plasma exposed to carbofuran with satisfactory specificity. The quantitation approach was established with d-carbofuran-exposed plasma as the internal standard (IS) and the linearity range was 30.0-1.00 × 10 nmol/L (R >0.998) with the accuracy of 95.6%-107% and precision of ≤9% relative standard deviation (RSD). The applicability was also evaluated by N,N-dimethyl-carbamates with the LODs of 30.0 nmol/L for pirimicarb-exposed plasma based on dimethylcarbamyl nonapeptide. Because most of carbamate toxicants has methylcarbamyl or dimethylcarbamyl groups, this approach could be applied on the retrospective screening of carbamate toxicant exposure including CMNAs, carbamate pesticides or carbamate drugs. This study could provide an effective means in the fields of CWC verification, toxicological mechanism investigation and down-selection of potential treatment options.
Topics: Humans; Butyrylcholinesterase; Chromatography, High Pressure Liquid; Tandem Mass Spectrometry; Retrospective Studies; Carbofuran; Acetylcholinesterase; Pepsin A; Nerve Agents; Pesticides
PubMed: 37285767
DOI: 10.1016/j.jchromb.2023.123775 -
Pharmaceuticals (Basel, Switzerland) Mar 2023Carbamate pesticides are a risk to human well-being, and pirimicarb is the most widely employed carbamate insecticide. This ongoing investigation aimed to reveal its...
Carbamate pesticides are a risk to human well-being, and pirimicarb is the most widely employed carbamate insecticide. This ongoing investigation aimed to reveal its toxicity on neurobehavioral and reproductive function. The study was carried out on male Wistar rats by assessment of behavioral changes via experiments, such as the forced swim test and the elevated plus maze; determination of oxidative stress (checking parameters such as catalase activity, etc.); measurement of cortisol and testosterone serum titers, and IL-1β levels in the plasma and brain; and evaluation of histopathological lesions that induced pirimicarb after 28 days of gavage, specifically in the brain and testis. Traces of pirimicarb were analyzed in tissue extracts using LCMS/MS. At the same time, the beneficial and protective effect of EamCE ( monjauzeana Crude Extract) were tested. The outcomes showed considerable anxiety and depressive status, with an evident increase in cortisol and IL-1β titers and an important decrease in oxidative enzymes and testosterone. Significant histological lesions were also recorded. In addition, the LCMS/MS analysis affirmed the accumulation of pirimicarb in organ tissue from rats force-fed with pirimicarb. Conversely, EamCE demonstrated outstanding potential as a preventive treatment, restoring cognitive and physical performance, boosting fertility, enhancing antioxidant and anti-inflammatory activities and preserving tissue integrity. We concluded that pirimicarb has critical deleterious impacts on health, affecting the neuroimmune-endocrine axis, and EamCE has a general euphoric and preventive effect.
PubMed: 36986501
DOI: 10.3390/ph16030402 -
EFSA Journal. European Food Safety... Feb 2023On 26 August 2022, the European Commission asked EFSA to provide scientific and technical assistance according to Article 21(2) of Regulation (EC) No 1107/2009...
On 26 August 2022, the European Commission asked EFSA to provide scientific and technical assistance according to Article 21(2) of Regulation (EC) No 1107/2009 concerning the review of the approval of the active substance pirimicarb and to deliver a statement on whether the applicable approval criteria may still be considered fulfilled, taking into consideration the information submitted by the applicant and the assessment of the rapporteur Member State, Sweden and, where applicable, the results of a discussion with experts from Member States. The current statement contains a summary of the main findings of the assessment of the risks to consumers from the exposure to metabolites of pirimicarb through dietary intake, the risks to human health through non-dietary exposure and the acute risk to birds from the representative uses of pirimicarb assessed for the first approval and additionally, from the representative uses as submitted as part of the renewal of approval. Concerns are reported where identified.
PubMed: 36818643
DOI: 10.2903/j.efsa.2023.7807 -
Polymers Jan 2023An electrochemical sensor for the pesticide Pirimicarb (PMC) has been developed. A screen-printed electrode (SPCE) was used and modified with the conducting polymer poly...
An electrochemical sensor for the pesticide Pirimicarb (PMC) has been developed. A screen-printed electrode (SPCE) was used and modified with the conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT) and gold nanoparticles (AuNPs) to enhance electrochemical proprieties. Electrode characterizations were performed using scattering electron microscopy (SEM) and cyclic voltammetry (CV). With the SPCE/PEDOT:PSS/AuNPs modified electrode, a new peak at 1.0 V appeared in the presence of PMC related to the PMC oxidation. To elucidate the mechanism of PMC oxidation, Gas Chromatography-Mass Spectrometry (GC-MS), where two major peaks were identified, evidencing that the device can both detect and degrade PMC by an electro-oxidation process. Exploring this peak signal, it was possible the sensor development, performing detection from 93.81-750 µmol L, limits of quantification (LOQ) and detection (LOD) of 93.91 µmol L and 28.34 µmol L, respectively. Thus, it was possible to study and optimization of PMC degradation, moreover, to perform detection at low concentrations and with good selectivity against different interferents using a low-cost printed electrode based on graphite modified with conductive polymer and AuNPs.
PubMed: 36772040
DOI: 10.3390/polym15030739 -
Chemosphere Mar 2023Due to their extensive use and high biological activity, insecticides largely contribute to loss of biodiversity and environmental pollution. The regulation of...
Due to their extensive use and high biological activity, insecticides largely contribute to loss of biodiversity and environmental pollution. The regulation of insecticides by authorities is mainly focused on lethal concentrations. However, sub-lethal effects such as alterations in behavior and neurodevelopment can significantly affect the fitness of individual fish and their population dynamics and therefore deserve consideration. Moreover, it is important to understand the impact of exposure timing during development, about which there is currently a lack of relevant knowledge. Here, we investigated whether there are periods during neurodevelopment of fish, which are particularly vulnerable to insecticide exposure. Therefore, we exposed zebrafish embryos to six different insecticides with cholinergic mode of action for 24 h during different periods of neurodevelopment and measured locomotor output using an age-matched behavior assay. We used the organophosphates diazinon and dimethoate, the carbamates pirimicarb and methomyl as well as the neonicotinoids thiacloprid and imidacloprid because they are abundant in the environment and cholinergic signaling plays a major role during key processes of neurodevelopment. We found that early embryonic motor behaviors, as measured by spontaneous tail coiling, increased upon exposure to most insecticides, while later movements, measured through touch-evoked response and a light-dark transition assay, rather decreased for the same insecticides and exposure duration. Moreover, the observed effects were more pronounced when exposure windows were temporally closer to the performing of the respective behavioral assay. However, the measured behavioral effects recovered after a short period, indicating that none of the exposure windows chosen here are particularly critical, but rather that insecticides acutely interfere with neuronal function at all stages as long as they are present. Overall, our results contribute to a better understanding of risks posed by cholinergic insecticides to fish and provide an important basis for the development of safe regulations to improve environmental health.
Topics: Animals; Insecticides; Zebrafish; Diazinon; Cholinergic Agents; Phenotype
PubMed: 36646183
DOI: 10.1016/j.chemosphere.2023.137874 -
Environmental Monitoring and Assessment Jan 2023Pesticides are the potent agrochemicals used to successfully manage, repel, or stop pests and weeds in agricultural production. This study analyzed 222 pesticide active...
Pesticides are the potent agrochemicals used to successfully manage, repel, or stop pests and weeds in agricultural production. This study analyzed 222 pesticide active substances in 90 samples of seven different vegetables and fruits acquired from producers through liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) and gas chromatography-mass spectrometry/mass spectrometry (GC-MS/MS) technology. The validation parameters of each pesticide's active substances were determined. The LOD, LOQ values, and recovery studies of the 222 active substances were 3.00, 10.00 ng/g, and between 76.07 and 108.08%, respectively. The correlation coefficients and measurement uncertainty were determined to be between 0.990-0.999 and 8.91-31.46%, respectively. There were active substances of chlorpyrifos, acetamiprid, azoxystrobin, difenoconazole, malathion, dieldrin, boscalid, triticonazole, tebuconazole, triadimenol, trifloxystrobin, pirimicarb, and dodine among the vegetable and fruit samples used in the study. There were no active substances in 55 (61%) samples. Among the 35 samples (39%), 31 samples (34%) contained only one active substance, whereas four (5%) contained two active substances. However, the amount of active substances in six (7%) samples was above the maximum residue levels (MRL) limits. Various processes used in the study revealed that peeling was the most effective pesticide residue removal strategy. The washing procedure also proved that it reduced some pesticide residues but failed to eliminate all pesticides. The peeling process successfully reduced a significant amount of the active substances from the products, however, residues remained. Washing the fruits with hot water was also effective in removing residues. As a result, analyses of the peeled sections yielded higher pesticide residue concentrations than those of the entire product.
Topics: Pesticide Residues; Tandem Mass Spectrometry; Fruit; Vegetables; Chromatography, Liquid; Gas Chromatography-Mass Spectrometry; Environmental Monitoring; Pesticides; Food Contamination
PubMed: 36609771
DOI: 10.1007/s10661-022-10910-2 -
Analytical Methods : Advancing Methods... Nov 2022Zeolitic imidazolate framework-8 modified magnetic halloysite nanotube (MHNTs@ZIF-8) composites were synthesized and evaluated for the first time as an efficient sorbent...
Zeolitic imidazolate framework-8 modified magnetic halloysite nanotube-based solid phase extraction for the analysis of carbamate pesticides by ultra-high performance liquid chromatography tandem mass spectrometry.
Zeolitic imidazolate framework-8 modified magnetic halloysite nanotube (MHNTs@ZIF-8) composites were synthesized and evaluated for the first time as an efficient sorbent for the magnetic solid-phase extraction (mSPE) of carbamate pesticides (CPs) from water samples. MHNTs were prepared by coprecipitation, and MHNTs@ZIF-8 composites were assembled at room temperature. After characterization, MHNTs@ZIF-8 was used to extract pirimicarb, propoxur, carbaryl, isoprocarb and fenobucarb π-π stacking interaction and hydrophobic interaction between the imidazole skeleton of ZIF-8 and benzene rings or benzene-like rings in CPs, as well as the hydrogen bond formed between O in CPs and H in ZIF-8. The effects of the amount of sorbent, ionic strength, type and volume of desorption solvent and adsorption/desorption time were investigated. Under optimum conditions, good linearity was obtained for the analysis of CPs by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) with ≥ 0.9992. The limits of quantification range from 3 to 40 ng L in water. Relative standard deviations (RSDs) were <7%, = 5, within a batch and <9% among batches. The spiked recoveries were between 81 and 104%. The proposed method has been successfully applied to the determination of CPs in various water samples.
Topics: Chromatography, High Pressure Liquid; Zeolites; Tandem Mass Spectrometry; Clay; Benzene; Water Pollutants, Chemical; Solid Phase Extraction; Pesticides; Carbamates; Esters; Nanotubes; Water; Magnetic Phenomena
PubMed: 36342027
DOI: 10.1039/d2ay01228f -
Environmental Toxicology and Chemistry Jan 2023Exposure of freshwater ecosystems to insecticides can negatively impact the development of emerging aquatic insects. These insects serve as an important nutritional...
Exposure of freshwater ecosystems to insecticides can negatively impact the development of emerging aquatic insects. These insects serve as an important nutritional subsidy for terrestrial insectivores. Changes in insect emergence phenology (i.e., emergence success and temporal pattern) or fluxes of insecticides retained by the emerging adults have the potential to negatively impact terrestrial food webs. These processes are influenced by contaminant toxicity, lipohilicity, or metabolic processes. The interplay between emergence phenology, contaminant retention through metamorphosis, and associated contaminant flux is not yet understood for current-use insecticides. In a microcosm study, we evaluated the impacts of a 24-h pulse exposure of one of three current-use insecticides, namely pirimicarb, indoxacarb, and thiacloprid, at two environmentally realistic concentration levels on the larval development and emergence of the nonbiting midge Chironomus riparius. In addition, we measured insecticide concentrations in the larvae and adults using ultrahigh performance liquid chromatography coupled to tandem mass spectrometry by electrospray ionization. Exposure to pirimicarb delayed larval development and emergence, and exposure to indoxacarb reduced emergence success. The neonicotinoid thiacloprid had the greatest impact by reducing larval survival and emergence success. At the same time, thiacloprid was the only insecticide measured in the adults with average concentrations of 10.3 and 37.3 ng/g after exposure at 0.1 and 4 µg/L, respectively. In addition, an approximate 30% higher survival to emergence after exposure to 0.1 µg/L relative to a 4-µg/L exposure resulted in a relatively higher flux of thiacloprid, from the aquatic to the terrestrial environment, at the lower exposure. Our experimental results help to explain the impacts of current-use insecticides on aquatic-terrestrial subsidy coupling and indicate the potential for widespread dietary exposure of terrestrial insectivores preying on emerging aquatic insects to the neonicotinoid thiacloprid. Environ Toxicol Chem 2023;42:60-70. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
Topics: Animals; Insecticides; Chironomidae; Ecosystem; Neonicotinoids; Insecta; Larva
PubMed: 36205389
DOI: 10.1002/etc.5495 -
Analytical Methods : Advancing Methods... Oct 2022Carbamate (CB) pesticides possess potential carcinogenic and mutagenic activities towards humans even at very low dosages. Thus, broad-specificity probes with high...
Carbamate (CB) pesticides possess potential carcinogenic and mutagenic activities towards humans even at very low dosages. Thus, broad-specificity probes with high sensitivity and speed are needed for multiple CB determination. This study is the first to focus on Dy ions-coordinated self-assembly on a silica core using a surface imprinting procedure, for the simultaneous fluorometric detection of residues of metolcarb (MC) and pirimicarb (PC) insecticides. A simple and mild solvothermal method was applied for the preparation of fluorescent imprinted microspheres starting from 1,10-phenanthroline (Phen)-ligated Dy ions to guide imprinted self-assembly of chitosan (CTS), glutaraldehyde (GA), and two carbamate pesticides (MC and PC) on the silica surface by means of coordinate bonds and hydrogen bonds. The as-prepared microspheres displayed strong fluorescence emissions the antenna effect derived from the Phen ligand and the Schiff base oligomers for sensitizing the Dy ions. An expanded in-depth mechanism study was performed on the fluorescence enhancement involving Förster resonance energy transfer (FRET) from the pesticides (donor) to the acceptor. A linear increase in fluorescence at 483 nm for MC and 574 nm for PC upon the imprinted microspheres was observed under the same 350 nm excitation wavelength. Moreover, the quantitative recognition process could be carried out simultaneously and tolerate strong distractions both from five other similar carbamate insecticides and from complicated matrices (, an extract of Ramat). The detection limit was 4 ng mL with a range of 10-60 ng mL for MC and 0.4 ng mL with a range of 1-30 ng mL for PC. Further characterization of the material, including TEM, SEM, XPS, and FTIR, Raman, and fluorescence spectra, verified that the Dy ions play a decisive role in promoting imprinted self-assembly around the silica core. Hence, a novel polynuclear Ln-organic imprinted probe having high selectivity, stability, and sensitivity for the detection of two carbamate insecticides is presented in this study.
Topics: Humans; Silicon Dioxide; Microspheres; Molecular Imprinting; Insecticides; Pesticides; Carbamates
PubMed: 36197096
DOI: 10.1039/d2ay01269c