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Scientific Reports May 2024In this study, a sensitive and selective fluorescent chemosensor was developed for the determination of pirimicarb pesticide by adopting the surface molecular imprinting...
In this study, a sensitive and selective fluorescent chemosensor was developed for the determination of pirimicarb pesticide by adopting the surface molecular imprinting approach. The magnetic molecularly imprinted polymer (MIP) nanocomposite was prepared using pirimicarb as the template molecule, CuFeO nanoparticles, and graphene quantum dots as a fluorophore (MIP-CuFeO/GQDs). It was then characterized using X-ray diffraction (XRD) technique, Fourier transforms infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), and transmission electron microscopy (TEM). The response surface methodology (RSM) was also employed to optimize and estimate the effective parameters of pirimicarb adsorption by this polymer. According to the experimental results, the average particle size and imprinting factor (IF) of this polymer are 53.61 nm and 2.48, respectively. Moreover, this polymer has an excellent ability to adsorb pirimicarb with a removal percentage of 99.92 at pH = 7.54, initial pirimicarb concentration = 10.17 mg/L, polymer dosage = 840 mg/L, and contact time = 6.15 min. The detection of pirimicarb was performed by fluorescence spectroscopy at a concentration range of 0-50 mg/L, and a sensitivity of 15.808 a.u/mg and a limit of detection of 1.79 mg/L were obtained. Real samples with RSD less than 2 were measured using this chemosensor. Besides, the proposed chemosensor demonstrated remarkable selectivity by checking some other insecticides with similar and different molecular structures to pirimicarb, such as diazinon, deltamethrin, and chlorpyrifos.
Topics: Pesticides; Carbamates; Quantum Dots; Molecularly Imprinted Polymers; Polymers; Spectrometry, Fluorescence; Graphite; Molecular Imprinting; Adsorption; Limit of Detection; Spectroscopy, Fourier Transform Infrared; Nanocomposites; Pyrimidines
PubMed: 38704412
DOI: 10.1038/s41598-024-60748-6 -
Insects Sep 2023The invasive apricot aphid ( Matsumura) is an important pest of apricot trees ( L.). In the presented study, laboratory bioassays using treated leaf disks of apricot...
The invasive apricot aphid ( Matsumura) is an important pest of apricot trees ( L.). In the presented study, laboratory bioassays using treated leaf disks of apricot were conducted to test the efficacy of twelve insecticides according to the maximum field dose. Additionally, dose-response curves were established for selected insecticides, and the effects on colony development were evaluated. Furthermore, a field trial was conducted to investigate the effectiveness of commonly used insecticides in apricot cultivation. The dose-response curves showed LC values ranging from 0.08 mg/L for flupyradifurone, 0.15 mg/L for acetamiprid, 0.70 mg/L for etofenprox, 1.89 mg/L for sulfoxaflor, 2.64 mg/L for pirimicarb, 3.97 mg/L for deltamethrin, up to 6.79 mg/L for tau-fluvalinate. These aforementioned insecticides resulted in mortality rates ranging from 95 to 100% at the field dose. Azadirachtin, flonicamid, and pyrethrins showed mortality rates of 27 to 45%. Spirotetramat reduced the colony development and decreased the number of infested shoots by 86%. Spinosad, which is not recommended against aphids, showed minimal impact; reducing the number of exuviae in nymphs in the colony development bioassay. It can be concluded that the majority of the tested insecticides are effective against .
PubMed: 37754715
DOI: 10.3390/insects14090746 -
Foods (Basel, Switzerland) Aug 2023In this study, a new approach to pesticide permeation through the apple peel into the pulp is discussed. The tested compounds can be classified, based on mode of action,...
In this study, a new approach to pesticide permeation through the apple peel into the pulp is discussed. The tested compounds can be classified, based on mode of action, as systemic (boscalid, cyprodinil, pirimicarb, propiconazole and tebuconazole) or contact (captan, cypermethrin and fludioxonil) pesticides. The barrier effect was assessed using a Franz flow-type vertical diffusion cell system. A residue analysis was performed using a modified quick, easy, cheap, efficient, rugged and safe (QuEChERS) extraction method coupled to gas chromatography with tandem mass spectrometry (GC-MS/MS). The limits of detection (LODs) ranged between 2.6 µg kg (pirimicarb) and 17 µg kg (captan), with the coefficient of variability (CV) lower than 6%, while recoveries ranged from 85% (boscalid) to 112% (captan) at 0.1 and 1 mg kg spiked levels. The highest peel penetration was observed for pirimicarb, captan and cyprodinil, with cumulative permeations of 90, 19 and 17 µg cm, respectively. The total absorption was in the range from 0.32% (tebuconazole) to 32% (pirimicarb). Only cypermethrin was not quantitatively detected in the pulp, and its use can be recommended in crop protection techniques. The obtained results indicate that molecular weight, octanol-water partition coefficient and water solubility are important parameters determining the process of pesticide absorption.
PubMed: 37685153
DOI: 10.3390/foods12173220 -
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 -
Nanomaterials (Basel, Switzerland) Aug 2022A three-steps sol-gel method was used to obtain a CuO/SnO/WO heterostructure powder, deposited as film by spray pyrolysis. The porous morphology of the final...
A three-steps sol-gel method was used to obtain a CuO/SnO/WO heterostructure powder, deposited as film by spray pyrolysis. The porous morphology of the final heterostructure was constructed starting with fiber-like WO acting as substrate for SnO development. The SnO/WO sample provide nucleation and grew sites for CuO formation. Diffraction evaluation indicated that all samples contained crystalline structures with crystallite size varying from 42.4 Å (CuO) to 81.8 Å (WO). Elemental analysis confirmed that the samples were homogeneous in composition and had an oxygen excess due to the annealing treatments. Photocatalytic properties were tested in the presence of three pesticides-pirimicarb, S-metolachlor (S-MCh), and metalaxyl (MET)-chosen based on their resilience and toxicity. The photocatalytic activity of the CuO/SnO/WO heterostructure was compared with WO, SnO, CuO, CuO/SnO, CuO/WO, and SnO/WO samples. The results indicated that the three-component heterostructure had the highest photocatalytic efficiency toward all pesticides. The highest photocatalytic efficiency was obtained toward S-MCh (86%) using a CuO/SnO/WO sample and the lowest correspond to MET (8.2%) removal using a CuO monocomponent sample. TOC analysis indicated that not all the removal efficiency could be attributed to mineralization, and by-product formation is possible. CuO/SnO/WO is able to induce 81.3% mineralization of S-MCh, while CuO exhibited 5.7% mineralization of S-MCh. The three-run cyclic tests showed that CuO/SnO/WO, WO, and SnO/WO exhibited good photocatalytic stability without requiring additional procedures. The photocatalytic mechanism corresponds to a Z-scheme charge transfer based on a three-component structure, where CuO exhibits reduction potential responsible for O production and WO has oxidation potential responsible for HO· generation.
PubMed: 35957078
DOI: 10.3390/nano12152648 -
Environmental Health Insights 2022This study assessed concentrations of pesticide residues in fruits and vegetables from farm-to-fork in Kampala Metropolitan Area, Uganda. A total of 160 samples of fruit...
This study assessed concentrations of pesticide residues in fruits and vegetables from farm-to-fork in Kampala Metropolitan Area, Uganda. A total of 160 samples of fruit and vegetables collected from farms, markets, streets, restaurants and homes were analysed using liquid chromatography-tandem mass spectrometry; and Gas Chromatograph-Mass Spectrometer for dithiocarbamates. Multiple pesticide residues were detected in majority of the samples (95.6%). The proportions of the most frequently detected pesticides residue classes were organophosphates (91.3%), carbamates (67.5%), pyrethroids (60.0%) dithiocarbamates (48.1%) and neonicotinoids (42.5%). Among organophosphates, propotamophos, acephate, fonofos, monocrotophos and dichlorvos were the most detected active ingredients; aminocarb, methomyl and pirimicarb were the commonly detected carbamates; while imidacloprid, a neonicotinoid and lambda-cyhalothrin, pyrethroid were also highly detected. Twenty-seven pesticide were tested at all stages, of which the concentrations either decreased or increased along the chain. Multiple pesticide residues occurred in commonly consumed fruit and vegetables with decreasing or increasing concentrations from farm-to-fork.
PubMed: 35846167
DOI: 10.1177/11786302221111866