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RSC Advances Mar 2024A fast, simple, and selective colorimetric assay for quantifying cypermethrin in water samples is proposed using l-cysteine functionalized gold nanoparticles...
A fast, simple, and selective colorimetric assay for quantifying cypermethrin in water samples is proposed using l-cysteine functionalized gold nanoparticles (AuNPs@Cyst). Cypermethrin is hydrolyzed by potassium hydroxide to obtain hydrolyzed cypermethrin in the form of 3-phenoxybenzaldehyde by-product (HCy). The detection strategy is based on the aggregation of AuNPs@Cyst caused by hydrogen-bonding recognition between the aldehyde group of HCy and the amine group of l-cysteine on the surface of AuNPs@Cyst. As a result, in the presence of HCy under optimal pH 7, AuNPs@Cyst aggregates within 7 min, exhibiting a distinct color change from red to blue-gray, which can be evaluated with the naked eye and UV-visible spectrophotometry. From FE-TEM image, the stable and spherical AuNPs@Cyst had an average size of 13.8 ± 1.6 nm, and from zeta potential analysis, the charge of AuNPs@Cyst was -25.04 ± 1.66 mV. The surface plasmon resonance band of dispersed AuNPs@Cyst was red shifted from 525 nm to 634 nm when AuNPs@Cyst was aggregated. The absorbance ratio (/) was linearly related to cypermethrin concentrations from 0.5 to 13.0 mg L. The limit of detection was 0.2 mg L and precision, expressed as relative standard deviations (RSDs), ranged from 1.9 to 7.3%. In the presence of interfering pesticides (carbaryl, ethion, profenofos and abamectin), only cypermethrin produced a significantly different response, confirming the selectivity of AuNPs@Cyst. Finally, AuNPs@Cyst was applied to determine cypermethrin in water samples, achieving very satisfied recoveries (>98.6%) and RSDs lower than 6.1%.
PubMed: 38500611
DOI: 10.1039/d3ra07626a -
Environmental Monitoring and Assessment Feb 2024Pesticides are of immense importance in agriculture, but they might contaminate bees' products. In this study, samples of honey, pollen, and beeswax were collected,...
Pesticides are of immense importance in agriculture, but they might contaminate bees' products. In this study, samples of honey, pollen, and beeswax were collected, seasonally, from apiaries in Toshka (Aswan), El-Noubariya (El-Beheira), and Ismailia (Ismailia) cities in Egypt. The pesticide residues were analyzed using the GC-MS after being extracted and cleaned using the QuEChERS method. Results showed that samples from El-Noubariya had great content of residues followed by Ismailia, and finally Toshka. Samples collected during fall and winter had the highest pesticide residue contents. Specifically, the phenylconazole fungicide group was repeatedly detected in all the examined samples along with organophosphate insecticides. Beeswax samples had the greatest amounts of pesticide residues followed by pollen and then honey samples. Chlorpyrifos (0.07-39.16 ng/g) and profenofos (1.94-17.00 ng/g) were detected in honey samples and their products. Pyriproxyfen (57.12 ng/g) and chlorpyrifos-methyl (39.16 ng/g) were detected in great amounts in beeswax samples from Ismailia and El-Noubariya, respectively. Yet, according to health hazard and quotient studies, the amounts of pesticides detected in honey do not pose any health threats to humans.
Topics: Humans; Bees; Animals; Pesticide Residues; Egypt; Seasons; Environmental Monitoring; Pesticides; Insecticides
PubMed: 38388839
DOI: 10.1007/s10661-024-12451-2 -
Heliyon Feb 2024In this work, a novel ternary nanocomposite of PEI/RuSi-MWCNTs was designed and synthesized for the first time, which an ultrasensitive and self-enhanced...
In this work, a novel ternary nanocomposite of PEI/RuSi-MWCNTs was designed and synthesized for the first time, which an ultrasensitive and self-enhanced electrochemiluminescent (ECL) aptasensor was developed for the detection of profenofos residues in vegetables. The self-enhanced complex PEI-Ru (II) enhanced the emission and stability of ECL, and the multi-walled carbon nanotubes (MWCNTs) acted as an excellent carrier and signal amplification. The PEI/RuSi-MWCNTs were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive spectrometer (EDS). The incorporation of gold nanoparticles (AuNPs) improved the performance of the sensor and provided a platform for the immobilization of the aptamer. The results of the experiment showed that the presence of profenofos significantly suppressed the electrochemiluminescence intensity of the sensor. The detection sensitivity of the aptamer sensor was in the range of 1 × 10 to 1 × 10 ng/mL. Under optimal conditions, the limit of detection (LOD) of the sensor for profenofos was 1.482 × 10 ng/mL. The sensor had excellent stability, reproducibility and specificity. The recoveries of the sensor ranged from 92.29 % to 106.47 % in real sample tests.
PubMed: 38333799
DOI: 10.1016/j.heliyon.2024.e25167 -
Scientific Reports Jan 2024Profenofos (PF) and captan (CT) are among the most utilized organophosphorus insecticides and phthalimide fungicides, respectively. To elucidate the physicochemical and...
Profenofos (PF) and captan (CT) are among the most utilized organophosphorus insecticides and phthalimide fungicides, respectively. To elucidate the physicochemical and influential toxicokinetic factors, the mechanistic interactions of serum albumin and either PF or CT were carried out in the current study using a series of spectroscopy and computational analyses. Both PF and CT could bind to bovine serum albumin (BSA), a representative serum protein, with moderate binding constants in a range of 10-10 M. The bindings of PF and CT did not induce noticeable BSA's structural changes. Both pesticides bound preferentially to the site I pocket of BSA, where the hydrophobic interaction was the main binding mode of PF, and the electrostatic interaction drove the binding of CT. As a result, PF and CT may not only induce direct toxicity by themselves, but also compete with therapeutic drugs and essential substances to sit in the Sudlow site I of serum albumin, which may interfere with the pharmacokinetics and equilibrium of drugs and other substances causing consequent adverse effects.
Topics: Protein Binding; Spectrometry, Fluorescence; Captan; Pesticides; Molecular Docking Simulation; Serum Albumin; Serum Albumin, Bovine; Binding Sites; Thermodynamics; Circular Dichroism; Organothiophosphates
PubMed: 38245578
DOI: 10.1038/s41598-024-52169-2 -
Food Chemistry: X Dec 2023The worldwide demand for organophosphorus pesticides (OPs) in food production has raised concerns about pesticide residues. Meta-analysis, proven effective in assessing...
The worldwide demand for organophosphorus pesticides (OPs) in food production has raised concerns about pesticide residues. Meta-analysis, proven effective in assessing contaminants like aflatoxins and organotin compounds, is applied here to comprehensively study OP contamination in fresh fruits and vegetables. Employing Comprehensive Meta-Analysis V3.0 software, we meticulously examined 24 relevant articles encompassing 69,467 data points. Our findings revealed that while the residual concentrations of OPs (such as chlorpyrifos and profenofos) in most fruits and vegetables have typically met international or national safety standards, including Codex Alimentarius Commission, European Union, British, and Chinese standards, there are some instances in which the maximum residue limits have been exceeded, posing safety risks. Therefore, significant efforts are required to maintain residual OP contamination at safe concentrations.
PubMed: 38144849
DOI: 10.1016/j.fochx.2023.101014 -
EFSA Journal. European Food Safety... Dec 2023In accordance with Article 43 of Regulation (EC) 396/2005, EFSA received a request from the European Commission to review the existing maximum residue levels (MRLs) for...
In accordance with Article 43 of Regulation (EC) 396/2005, EFSA received a request from the European Commission to review the existing maximum residue levels (MRLs) for the non-approved active substance profenofos in view of the possible lowering of the MRL. EFSA investigated the origin of the current EU MRLs. Existing EU MRLs are based on Codex Maximum Residue Limits still in place or reflect temporary MRLs set from monitoring data. EFSA performed an indicative chronic and acute dietary risk assessment for the list of MRLs to allow risk managers to take the appropriate decisions. For some commodities, further risk management discussions are required to decide which of the risk management options proposed by EFSA should be implemented in the EU MRL legislation.
PubMed: 38046200
DOI: 10.2903/j.efsa.2023.8445 -
Food Chemistry: X Oct 2023This study developed a method to simultaneously determine 73 multi-class pesticides in okra fruit using LC-MS/MS and GC-MS/MS. The sample was extracted with acetonitrile...
This study developed a method to simultaneously determine 73 multi-class pesticides in okra fruit using LC-MS/MS and GC-MS/MS. The sample was extracted with acetonitrile and subsequent clean-up through dispersive-SPE method. The quantification level of the technique was 0.01 µg g and compliance to the MRLs fixed by the regulatory bodies like EU and FSSAI. The recovery at 10, 50, and 100 µg kg spiked levels; intra and inter-day precision at 50 µg kg were found within 70-120% with RSD less than 15% with LC-MS/MS and GC-MS/MS. Measurement uncertainty was in the range of 1.81 to 12.91 µg kg estimated at 50 µg kg. The matrix effects were slightly higher for LC than GC-compatible pesticides. Risk assessment for pesticides detected in the field and market samples found no hazardous to the consumers except profenofos. The proposed method is highly sensitive, reproducible for the complex matrix like okra, and meets the regulatory standards.
PubMed: 37780267
DOI: 10.1016/j.fochx.2023.100814 -
Foods (Basel, Switzerland) Sep 2023Pesticide residues in kumquat fruits from China, and the quality and chronic/acute intake risks in Chinese consumers, were assessed using the QuEChERS procedure and...
Pesticide residues in kumquat fruits from China, and the quality and chronic/acute intake risks in Chinese consumers, were assessed using the QuEChERS procedure and UHPLC-MS/MS and GC-MS/MS methods. Our 5-year monitoring and survey showed 90% of the 573 samples of kumquat fruits collected from two main production areas contained one or multiple residual pesticides. Overall, 30 pesticides were detected, including 16 insecticides, 7 fungicides, 5 acaricides, and 2 plant growth modulators, of which 2 pesticides were already banned. Two or more residual pesticides were discovered in 81% of the samples, and pesticide residues in 9.4% of the samples surpassed the , such as profenofos, bifenthrin, triazophos, avermectin, spirodiclofen, difenoconazole, and methidathion. The major risk factors on the safety of kumquat fruits before 2019 were profenofos, bifenthrin, and triazophos, but their over-standard frequencies significantly declined after 2019, which was credited to the stricter supervision and management policies by local governments. Despite the high detection rates and multi-residue occurrence of pesticides in kumquat fruits, about 81% of the samples were assessed as qualified. Moreover, the accumulative chronic diet risk determined from is very low. To better protect the health of customers, we shall formulate stricter organic phosphorus pesticide control measures and stricter use guidelines, especially for methidathion, triazophos, chlorpyrifos, and profenofos. This study provides potential data for the design of kumquat fruit quality and safety control guidelines and for the reduction in health risks to humans.
PubMed: 37761133
DOI: 10.3390/foods12183423 -
Analytica Chimica Acta Oct 2023Chlorpyrifos (CPF) is a commonly used insecticide found in many water sources and is related to several health and environmental effects. Biosensors based on aptamers...
Chlorpyrifos (CPF) is a commonly used insecticide found in many water sources and is related to several health and environmental effects. Biosensors based on aptamers (single-stranded nucleic acid oligonucleotides) are promising alternatives to achieve the detection of CPF and other pesticides in natural waters. However, several challenges need to be addressed to promote the real application of functional aptasensing devices. In this work, an ssDNA aptamer (S1) is combined with carbon quantum dots (CD) and graphene oxide (GO) to produce a stable fluorescent aptasensor characterized through spectrophotometric and electrophoretic techniques. For a deeper understanding of the system, the mechanism of molecular interaction was studied through docking modeling using free bioinformatic tools like HDOCK, showing that the stem-loops and the higher guanine (G) content are crucial for better interaction. The model also suggests the possibility of generating a truncated aptamer to improve the binding affinity. The biosensor was evaluated for CPF detection, showing a low LOD of 0.01 μg L and good specificity in tap water, even compared to other organophosphates pesticides (OPs) like profenofos. Finally, the recovery of the proposed aptasensor was evaluated in some natural water using spiked samples and compared with UPLC MS-MS chromatography as the gold standard, showing a good recovery above 2.85 nM and evidencing the need of protecting ssDNA aptamers from an erratic interaction with the aromatic groups of dissolved organic matter (humic substances). This work paves the way for a better aptasensors design and the on-site implementation of novel devices for environmental monitoring.
Topics: Chlorpyrifos; Carbon; Insecticides; Pesticides; Coloring Agents; DNA, Single-Stranded; Environmental Pollutants
PubMed: 37709453
DOI: 10.1016/j.aca.2023.341711 -
Chemosphere Oct 2023The Ecuadorian Amazon has experienced a significant land use change due to the demographic increase and the expansion of the agricultural frontier. Such changes in land...
The Ecuadorian Amazon has experienced a significant land use change due to the demographic increase and the expansion of the agricultural frontier. Such changes in land use have been associated to water pollution problems, including the emission of untreated urban wastewater and pesticides. Here we provide the first report on the influence of urbanization and intensive agriculture expansion on water quality parameters, pesticide contamination and the ecological status of Amazonian freshwater ecosystems of Ecuador. We monitored 19 water quality parameters, 27 pesticides, and the macroinvertebrate community in 40 sampling locations of the Napo River basin (northern Ecuador), including a nature conservation reserve and sites in areas influenced by African palm oil production, corn production and urbanization. The ecological risks of pesticides were assessed using a probabilistic approach based on species sensitivity distributions. The results of our study show that urban areas and areas dominated by African palm oil production have a significant influence on water quality parameters, affecting macroinvertebrate communities and biomonitoring indices. Pesticide residues were detected in all sampling sites, with carbendazim, azoxystrobin, diazinon, propiconazole and imidacloprid showing the largest prevalence (>80% of the samples). We found a significant effect of land use on water pesticide contamination, with residues of organophosphate insecticides correlating with African palm oil production and some fungicides with urban areas. The pesticide risk assessment indicated organophosphate insecticides (ethion, chlorpyrifos, azinphos-methyl, profenofos and prothiophos) and imidacloprid as the compounds posing the largest ecotoxicological hazard, with pesticide mixtures potentially affecting up to 26-29% of aquatic species. Ecological risks of organophosphate insecticides were more likely to occur in rivers surrounded by African palm oil plantations, while imidacloprid risks were identified in corn crop areas as well as in natural areas. Future investigations are needed to clarify the sources of imidacloprid contamination and to assess its effects for Amazonian freshwater ecosystems.
Topics: Pesticides; Ecuador; Insecticides; Water Quality; Ecosystem; Palm Oil; Urbanization; Environmental Monitoring; Water Pollutants, Chemical; Agriculture; Fresh Water; Rivers; Chlorpyrifos
PubMed: 37379974
DOI: 10.1016/j.chemosphere.2023.139286