RESUMO
Cowpea plants, renowned for their high edibility, pose a significant risk of pesticide residue contamination. Elucidating the behavior of pesticide residues and their key metabolic pathways is critical for ensuring cowpea safety and human health. This study investigated the migration of pesticide residues and their key metabolic pathways in pods throughout the growth process of cowpea plants via in situ mass spectrometry. To this end, four pesticides--including systemic (thiram), and nonsystemic (fluopyram, pyriproxyfen, and cyromazine) pesticides--were selected. The results indicate the direct upward and downward transmission of pesticides in cowpea stems and pods. Systemic pesticides gradually migrate to the core of cowpea plants, whereas nonsystemic pesticides remain on the surface of cowpea peels. The migration rate is influenced by the cowpea maturity, logarithmic octanol-water partition coefficient (log Kow) value, and molecular weight of the pesticide. Further, 20 types of key metabolites related to glycolysis, tricarboxylic acid cycle, and flavonoid synthesis were found in cowpea pods after pesticide treatment. These findings afford insights into improving cowpea quality and ensuring the safe use of pesticides.
Assuntos
Espectrometria de Massas , Resíduos de Praguicidas , Vigna , Vigna/crescimento & desenvolvimento , Vigna/metabolismo , Vigna/efeitos dos fármacos , Resíduos de Praguicidas/metabolismo , Resíduos de Praguicidas/análise , Redes e Vias MetabólicasRESUMO
Pesticides play vital roles in controlling pests and boosting crop yields. Imidacloprid is widely used all over the world and may form in agricultural products. The presence of pesticide residues in apples raises serious health concerns. Understanding the residual fate of imidacloprid is critical for food safety and human health. In this study, the dissipation behavior, metabolism, household processing and risk assessment of imidacloprid and its metabolites in apple were investigated from filed to products. Field experiment results suggested that the half-lives of imidacloprid at 5 times the recommended dosage was 1.5 times that of the standard dosage. And the final residues of imidacloprid were less than the established maximum residue limits (MRLs). Clarification and simmering had little effect on the reduction the residues of imidacloprid and its metabolites. The calculated processing factors were lower than 1 for imidacloprid and its metabolites, implying that the residual ratios of imidacloprid and its metabolites in each steps of the food processing were reduced. The risk quotients were <1 for all Chinese people, indicating that acceptable risks associated with dietary exposure to imidacloprid in apple. However, the higher risks were observed in young people than adults, and females faced higher risks than males. Given high residue levels in pomace, imidacloprid and its metabolites should be further studied in commercial byproducts.
Assuntos
Inseticidas , Malus , Neonicotinoides , Nitrocompostos , Resíduos de Praguicidas , Malus/química , Malus/metabolismo , Neonicotinoides/metabolismo , Neonicotinoides/análise , Nitrocompostos/análise , Nitrocompostos/metabolismo , Medição de Risco , Resíduos de Praguicidas/análise , Resíduos de Praguicidas/metabolismo , Inseticidas/análise , Inseticidas/metabolismo , Humanos , Contaminação de Alimentos/análise , Exposição Dietética/análise , China , Feminino , Imidazóis/metabolismo , Imidazóis/análise , Imidazóis/químicaRESUMO
Neonicotinoids are insecticides used worldwide in phytosanitary and biocidal products and veterinary pharmaceuticals. Recently, some restrictions and bans have been imposed due to their adverse effects on nontarget invertebrates, including pollinators. Although they may have direct and indirect effects on wild vertebrates, few studies have assessed exposure to these compounds in wild birds, so our knowledge remains limited. In the present pilot study we have assessed the prevalence of seven neonicotinoid insecticides and some of their metabolites in whole blood samples from 19 European roller (Coracias garrulus) nestlings and five adult common kestrels (Falco tinnunculus) in an area treated with neonicotinoids to control the palm weevil (Rynchophorus ferrugineus) in southeastern Spain. One European roller nestling born in a palm tree was positive for thiamethoxam, with a concentration of 2.26 ng mL-1, but no residues of neonicotinoids or their metabolites were found in adult common kestrels. Future studies are needed to elucidate potential exposure to neonicotinoids at different times of the year. To our knowledge, this is the first report of the presence of thiamethoxam residues in whole blood of a wild bird species after its ban in Spain. Environ Toxicol Chem 2024;43:1836-1843. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
Assuntos
Aves , Monitoramento Ambiental , Inseticidas , Tiametoxam , Tiametoxam/análise , Tiametoxam/metabolismo , Inseticidas/análise , Inseticidas/metabolismo , Aves/metabolismo , Espanha , Agricultura , Resíduos de Praguicidas/análise , Resíduos de Praguicidas/metabolismo , Gorgulhos , Neonicotinoides/análise , Neonicotinoides/metabolismo , Medição de RiscoRESUMO
Trichoderma can enhance the metabolism of organophosphate pesticides in plants, but the mechanism is unclear. Here, we performed high-throughput transcriptome sequencing of roots upon Trichoderma asperellum (TM) inoculation and phoxim (P) application in tomato (Solanum lycopersicum L.). A total of 4059 differentially expressed genes (DEGs) were obtained, including 2110 up-regulated and 1949 down-regulated DEGs in P vs TM+P. COG and KOG analysis indicated that DEGs were mainly enriched in signal transduction mechanisms. We then focused on the pesticide detoxification pathway and screened out cytochrome P450 CYP736A12 as a putative gene for functional analysis. We suppressed the expression of CYP736A12 in tomato plants by virus-induced gene silencing and analyzed tissue-specific phoxim residues, oxidative stress markers, glutathione pool, GST activity and related gene expression. Silencing CYP736A12 significantly increased phoxim residue and induced oxidative stress in tomato plants, by attenuating the TM-induced increased activity of antioxidant and detoxification enzymes, redox homeostasis and transcripts of detoxification genes including CYP724B2, GSH1, GSH2, GR, GPX, GST1, GST2, GST3, and ABC. The study revealed a critical mechanism by which TM promotes the metabolism of phoxim in tomato roots, which can be useful for further understanding the Trichoderma-induced xenobiotic detoxification and improving food safety.
Assuntos
Sistema Enzimático do Citocromo P-450 , Compostos Organotiofosforados , Raízes de Plantas , Solanum lycopersicum , Solanum lycopersicum/genética , Solanum lycopersicum/metabolismo , Solanum lycopersicum/efeitos dos fármacos , Solanum lycopersicum/crescimento & desenvolvimento , Sistema Enzimático do Citocromo P-450/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Raízes de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Compostos Organotiofosforados/toxicidade , Compostos Organotiofosforados/metabolismo , Resíduos de Praguicidas/toxicidade , Resíduos de Praguicidas/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Hypocreales/metabolismo , Hypocreales/genéticaRESUMO
Parallel to the important use of pesticides in conventional agriculture there is a growing interest for green technologies to clear contaminated soil from pesticides and their degradation products. Bioaugmentation i. e. the inoculation of degrading micro-organisms in polluted soil, is a promising method still in needs of further developments. Specifically, improvements in the understanding of how degrading microorganisms must overcome abiotic filters and interact with the autochthonous microbial communities are needed in order to efficiently design bioremediation strategies. Here we designed a protocol aiming at studying the degradation of two herbicides, glyphosate (GLY) and isoproturon (IPU), via experimental modifications of two source bacterial communities. We used statistical methods stemming from genomic prediction to link community composition to herbicides degradation potentials. Our approach proved to be efficient with correlation estimates over 0.8 - between model predictions and measured pesticide degradation values. Multi-degrading bacterial communities were obtained by coalescing bacterial communities with high GLY or IPU degradation ability based on their community-level properties. Finally, we evaluated the efficiency of constructed multi-degrading communities to remove pesticide contamination in a different soil. While results are less clear in the case of GLY, we showed an efficient transfer of degrading capacities towards the receiving soil even at relatively low inoculation levels in the case of IPU. Altogether, we developed an innovative protocol for building multi-degrading simplified bacterial communities with the help of genomic prediction tools and coalescence, and proved their efficiency in a contaminated soil.
Assuntos
Bactérias , Biodegradação Ambiental , Glicina , Glifosato , Herbicidas , Microbiologia do Solo , Poluentes do Solo , Poluentes do Solo/metabolismo , Glicina/análogos & derivados , Glicina/metabolismo , Bactérias/metabolismo , Bactérias/genética , Herbicidas/metabolismo , Herbicidas/química , Compostos de Fenilureia/metabolismo , Resíduos de Praguicidas/metabolismoRESUMO
By collecting real samples throughout the entire production process and employing chemometrics, metabolomics, and modern separation omic techniques, it unveiled the patterns of pesticide transfer during solid-state fermentation. The results indicated that 12 types of pesticide residues were prevalent during baijiu production, with organochlorine and carbamate pesticides being the most abundant in raw materials. After fermentation, organochlorine pesticides and pyrethroid pesticides exhibited higher content, while carbamate pesticides dominated in the final product. The pathways for pesticide input and elimination were identified, and the intricate mechanisms underlying these changes were further elucidated. Additionally, key control points were defined to facilitate targeted monitoring. The results indicated that pesticide residue primarily originates from raw materials and Daqu, whereas both solid-state fermentation and distillation processes were effective in reducing pesticide residues. The study offers valuable guidance for establishing pesticide residue standards in the context of baijiu production.
Assuntos
Fermentação , Metabolômica , Resíduos de Praguicidas , Resíduos de Praguicidas/metabolismo , Resíduos de Praguicidas/química , Resíduos de Praguicidas/análise , Contaminação de Alimentos/análise , QuimiometriaRESUMO
The study evaluated Ceremonia 25 EC®, a plant protection product (PPP) containing difenoconazole, in tomato crops, to identify potential risks associated with PPPs, and in addition to this compound, known metabolites from difenoconazole degradation and co-formulants present in the PPP were monitored. An ultra high performance liquid chromatography coupled to quadrupole-Orbitrap mass analyser (UHPLC-Q-Orbitrap-MS) method was validated with a working range of 2 µg/kg (limit of quantification, LOQ) to 200 µg/kg. Difenoconazole degradation followed a biphasic double first-order in parallel (DFOP) kinetic model in laboratory and greenhouse trials, with high accuracy (R2 > 0.9965). CGA-205374, difenoconazole-alcohol, and hydroxy-difenoconazole metabolites were tentatively identified and semi-quantified in laboratory trials by UHPLC-Q-Orbitrap-MS from day 2 to day 30. No metabolites were found in greenhouse trials. Additionally, 13 volatile co-formulants were tentatively identified by gas chromatography (GC) coupled to Q-Orbitrap-MS, detectable up to the 7th day after PPP application. This study provides a comprehensive understanding of difenoconazole dissipation in tomatoes, identification of metabolites, and detection of co-formulants associated with the applied PPP.
Assuntos
Dioxolanos , Fungicidas Industriais , Solanum lycopersicum , Triazóis , Solanum lycopersicum/metabolismo , Solanum lycopersicum/química , Dioxolanos/metabolismo , Triazóis/metabolismo , Triazóis/análise , Triazóis/química , Fungicidas Industriais/metabolismo , Fungicidas Industriais/análise , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas/métodos , Contaminação de Alimentos/análise , Resíduos de Praguicidas/análise , Resíduos de Praguicidas/metabolismoRESUMO
Pesticide residues in food crops are one of the seriously environmental contaminants that risk food safety and human health. Understanding the mechanism for pesticide catabolism is critical to develop effective biotechniques for rapid eliminating the residues in food crops. In this study we characterized a novel ABC transporter family gene ABCG52 (PDR18) in regulating rice response to pesticide ametryn (AME) widely used in the farmland. Efficient biodegradation of AME was evaluated by measuring its biotoxicity, accumulation, and metabolites in rice plants. OsPDR18 was localized to the plasma membrane and strongly induced under AME exposure. Transgenic rice overexpressing OsPDR18 (OE) conferred rice resistance and detoxification to AME by increasing chlorophyll contents, improving growth phenotypes, and reducing AME accumulation in plants. The AME concentrations in OE plants were only 71.8-78.1% (shoots) and 75.0-83.3% (roots) of the wild type. Mutation of OsPDR18 by CRISPR/Cas9 protocol led to the compromised growth and enhanced AME accumulation in rice. Five AME metabolites for Phase I and 13 conjugates for Phase II reactions in rice were characterized by HPLC/Q-TOF-HRMS/MS. Relative content analysis revealed that the AME metabolic products in OE plants were significantly reduced compared with wild-type. Importantly, the OE plants accumulated less AME metabolites and conjugates in rice grains, suggesting that OsPDR18 expression may actively facilitate the transport of AME for catabolism. These data unveil a AME catabolic mechanism by which OsPDR18 contributes to the AME detoxification and degradation in rice crops.
Assuntos
Oryza , Resíduos de Praguicidas , Praguicidas , Humanos , Oryza/metabolismo , Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Praguicidas/metabolismo , Resíduos de Praguicidas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Regulação da Expressão Gênica de PlantasRESUMO
Pollutants cause a huge problem for humans, animals, plants, and various ecosystems, especially water resources. Agricultural, domestic, and industrial waste effluents change the water quality and affect living microorganisms. Therefore, the current study aimed to identify possible microorganisms in wastewater as potential bioremediation agents of pesticide residues. Wastewater samples were collected from El-Khairy agricultural drainage, which receives agricultural and domestic wastes. Bacteria and fungi species were isolated as clean cultures. Wastewater samples were analyzed for pesticide residues via gas chromatography-mass spectroscopy (GC-MS) system. Results uncovered the presence of ten pesticides ranging from 0.0817 to 28.162 µg/l, and the predominant pesticide was chlorpyrifos. Along with that, about nine species (3 bacterial and 6 fungal) were relatively efficient in the removal of chlorpyrifos residues up to 2000 µg/l with removal percentages ranging from 24.16 to 80.93% under laboratory conditions. Two bacterial isolates proficiently degraded significant amounts of chlorpyrifos: Bacillus cereus strain PC2 (GenBank accession No. MZ314010) and Streptomyces praecox strain SP1 (GenBank accession No. MZ314009). In-site bacterial and fungal isolates defined in the current study were proficient in cleaning wastewater of chlorpyrifos pesticide residues.
Assuntos
Clorpirifos , Resíduos de Praguicidas , Praguicidas , Humanos , Animais , Águas Residuárias , Resíduos de Praguicidas/metabolismo , Biodegradação Ambiental , Ecossistema , Monitoramento Ambiental , Praguicidas/metabolismo , Bactérias/metabolismo , FungosRESUMO
Acetamiprid (ACE) and cyromazine (CYR) are the two pesticides that are used relatively frequently and in large quantities in cowpea growing areas in Hainan. The uptake, translocation and metabolic patterns and subcellular distribution of these two pesticides in cowpea are important factors affecting pesticide residues in cowpea and assessing the dietary safety of cowpea. In this study, we investigated the uptake, translocation, subcellular distribution, and metabolic pathway of ACE and CYR in cowpea under laboratory hydroponic conditions. The distribution trends of both ACE and CYR in cowpea plants were leaves > stems > roots. The distribution of both pesticides in subcellular tissues of cowpea was cell soluble fraction > cell wall > cell organelle, and both transport modes were passive. A multiplicity of metabolic reactions of both pesticides occurred in cowpea, including dealkylation, hydroxylation and methylation. The results of the dietary risk assessment indicate that ACE is safe for use in cowpeas, but CYR poses an acute dietary risk to infants and young children. This study provided a basis for insights into the transport and distribution of ACE and CYR in vegetables and contributes to the assessment of whether pesticide residues in vegetables could pose a potential threat to human health at high concentrations of pesticides in the environment.
Assuntos
Resíduos de Praguicidas , Praguicidas , Vigna , Criança , Humanos , Pré-Escolar , Vigna/química , Vigna/metabolismo , Resíduos de Praguicidas/metabolismo , Praguicidas/metabolismoRESUMO
Pesticide overuse has led to serious global concerns regarding food safety and environmental pollution. Although the reduction of pesticide residue is critical, our knowledge about induced pesticide metabolism in plants remains fragmentary. Melatonin (N-acetyl-5-methoxytryptamine) is an effective stress-relieving agent in both animals and plants, but little is known about the melatonin signaling mechanism and its effect on pesticide metabolism in plants. Here, we found that exogenous melatonin treatment significantly reduced chlorothalonil residue by 41 % but suppression of endogenous melatonin accumulation increased chlorothalonil residue in tomato leaves. Moreover, melatonin increased photosynthesis, Fv/Fm, Calvin cycle enzyme activity, antioxidant enzyme activity, glutathione pool, and RESPIRATORY BURST HOMOLOG1 (RBOH1) expression in tomato leaves. However, the upregulation of RBOH1, CYP724B2, GST1, GST2, GSH and ABC, the increased glutathione concentrations and the activity of detoxification enzymes due to melatonin treatment were all significantly attenuated by the treatment with an NADPH oxidase inhibitor and a ROS scavenger, indicating a clear relationship between the reduction of pesticide residue and induction in detoxifying enzymes and genes upon melatonin treatment in an apoplastic H2O2-dependent manner. These results reveal that melatonin-induced reduction in chlorothalonil residue is mediated by H2O2 signaling in tomato leaves.
Assuntos
Melatonina , Resíduos de Praguicidas , Praguicidas , Solanum lycopersicum , Solanum lycopersicum/metabolismo , Melatonina/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Peróxido de Hidrogênio/metabolismo , Resíduos de Praguicidas/metabolismo , Folhas de Planta/metabolismo , Antioxidantes/metabolismo , Glutationa/metabolismo , Praguicidas/metabolismoRESUMO
BACKGROUND: Thiamethoxam is widely used to control pests in Chinese kale, popularly consumed leafy vegetables. The potential risk to the environment and human health has aroused much public concern. Therefore, it is important to investigate the degradation behavior, residue distribution and dietary risk assessment of thiamethoxam in Chinese kale. RESULTS: A sensitive analytical method for determination of thiamethoxam and its metabolite clothianidin residue in Chinese kale was established and validated through a quick, easy, cheap, effective, rugged, and safe (QuEChERS) technique with ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The recoveries were 85.4-101.2% for thiamethoxam and 79.5-108.1% for clothianidin, with the relative standard deviations (RSDs) of 0.9-10.2% and 1.8-6.0%, respectively. For the dissipation kinetics, the data showed that thiamethoxam in Chinese kale was degraded with the half-lives of 4.1 to 4.5 days. In the terminal residue experiments, the residues of thiamethoxam were 0.017-0.357 mg kg-1 after application 2-3 times with a preharvest interval (PHI) of 7 days under the designed dosages. The chronic and acute dietary exposure assessment risk quotient (RQ) values of thiamethoxam in Chinese kale for different Chinese consumers were 0.08-0.19% and 0.05-0.12%, respectively, and those of clothianidin were 0.01-0.04% and 0.02-0.04%, respectively, all of the RQ values were lower than 100%. CONCLUSION: Thiamethoxam in Chinese kale was rapidly degraded following first-order kinetics models. The dietary risk of thiamethoxam and clothianidin through Chinese kale was negligible to consumers. The results from this study are important reference for Chinese governments to developing criteria for the safe and rational use of thiamethoxam, setting maximum residue levels (MRLs), monitoring the quality safety of agricultural products and protecting consumer health. © 2021 Society of Chemical Industry.
Assuntos
Brassica/química , Cromatografia Líquida/métodos , Guanidinas/metabolismo , Neonicotinoides/metabolismo , Resíduos de Praguicidas/química , Resíduos de Praguicidas/metabolismo , Espectrometria de Massas em Tandem/métodos , Tiametoxam/química , Tiametoxam/metabolismo , Tiazóis/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Brassica/metabolismo , Criança , Pré-Escolar , China , Exposição Dietética/efeitos adversos , Exposição Dietética/análise , Feminino , Contaminação de Alimentos/análise , Humanos , Cinética , Masculino , Pessoa de Meia-Idade , Medição de Risco , Verduras/química , Verduras/metabolismo , Adulto JovemRESUMO
A Sin-QuEChERS, coupled to UHPLC Q-Exactive Orbitrap MS, was used for nontargeted high-throughput rapid screening and quantitative analysis of residual pesticides and metabolites in green teas. The sample was extracted with 0.1% formic acid in acetonitrile with shaking, salted out and centrifuged, and purified with Sin-QuEChERS Nano solid phase extraction column; with Full MS/ddMS2 as the data collection mode, the database containing 384 pesticides combined with Trace Finder 3.0 software, In the absence of standard products, rapid screening and confirmation of potential pesticide residues in tea samples with accurate mass, isotope abundance ratio, secondary fragment ions, etc. 20 pesticides were used as quality controls to verify the screening method, and the linearity of these pesticides was between 1 and 200 µg/L, and the correlation coefficients were all greater than 0.9922. Moreover, the LOQ was between 0.002 and 0.01 mg/kg. The average recoveries of spiked tea samples were 74%-111%. Efficiency and reliability of this method were investigated by the analysis of 38 Chinese green tea samples. 18 potential residual pesticides were detected by non-targeted screening. The researchers then conducted a quantitative analysis of the 18 potential residual pesticides.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas/métodos , Resíduos de Praguicidas , Chá/química , Ensaios de Triagem em Larga Escala , Limite de Detecção , Modelos Lineares , Resíduos de Praguicidas/análise , Resíduos de Praguicidas/metabolismo , Reprodutibilidade dos TestesRESUMO
Amitraz, a member of the formamidine pesticide family, commonly used for ectoparasite control, is applied as a dip or low-pressure hand spray to cattle and swine, and the neck collar on dogs. Data on amitraz were generated mainly on laboratory animals, hens, dogs, and baboons. The data on the toxicity and disposition of amitraz in animals and its residues in the milk are inadequate. Therefore, the present study was intended to analyze the disposition kinetics of amitraz and its pattern of elimination in the milk of lactating does after a single dermal application at a concentration of 0.25%. Blood at predetermined time intervals and milk twice daily were collected for eight days post application. The drug concentration was assayed by high-performance liquid chromatography (HPLC). Amitraz was detected in whole blood as early as 0.5 h, which attained a peak concentration at 12 ± 5 h, followed by a steady decline; however, detection persisted until 168 h. Amitraz was present in the blood at its 50% Cmax even after 48 h, and was still detectable after 7 days. The disposition after a single dermal application was best described non-compartmentally. The mean terminal half-life (t1/2), mean residence time (MRT), and area under the curve (AUC0-t) were 111 ± 31 h, 168 ± 39 h, and 539 ± 211 µg/mL/h, respectively. The apparent volume of distribution (Vdarea) was 92 ± 36 mL/g with an observed clearance (Cl) of 0.57 ± 0.33 mL/kg/h. Thus, the drug was well absorbed, widely distributed and slowly eliminated from the animal body. Amitraz achieved milk concentration approximating 0.2 per cent of the total dose after a single exposure and the steady-state elimination of amitraz in milk above the recommended maximum residue limit (MRL) of 0.01 mg/kg can act as a source of public health concern when applied on lactating animals.
Assuntos
Cervos , Lactação , Resíduos de Praguicidas/metabolismo , Toluidinas/metabolismo , Animais , Ácidos Cólicos , Feminino , Meia-Vida , CinéticaRESUMO
Understanding of pesticide persistence and diffusion on the fresh vegetables are extremely important in food safety and decontamination process. In this study, we examine the persistence and diffusion behaviour of chlorpyrifos pesticide in five different species of vegetables. The chlorpyrifos pesticide was spiked on the vegetable surfaces and the extracted samples from peel and tissues were subjected to Gas Chromatography equipped with a Flame Photometric Detector (GC-FPD). Further, the chlorpyrifos diffusion behaviour was compared with the osmotic potential, shear strength, cuticular chemical profile and microstructure of peel surface of vegetables. The persistence analysis results revealed that chlorpyrifos level was decreased in peel surface and diffusion rate was increased in inner tissue with respect to durations. Within 72 h exposure, chlorpyrifos reached 0.7 cm depth into the inner tissue of vegetables. Significant level of chlorpyrifos diffusion with P ≤ 0.05 was observed in beetroot (2.47%), khon khol (1.46%) and brinjal (0.92%) compared to cucumber and potato. Remarkably, there was no direct linkage between the chlorpyrifos diffusion rate, osmotic potential and toughness of vegetables. In addition, the Gas Chromatography Mass Spectroscopy (GC-MS) and Scanning Electron Microscopy (SEM) analyses revealed that epicuticular surface microstructure and chemical profiles were not correlated with the chlorpyrifos diffusion in all the tested vegetables. The study results concludes that chlorpyrifos diffusion is vegetable species specific and it is highly variable between the species.
Assuntos
Clorpirifos/metabolismo , Resíduos de Praguicidas/metabolismo , Verduras/metabolismo , Clorpirifos/análise , Cromatografia Gasosa/métodos , Cucumis sativus , Contaminação de Alimentos/análise , Inocuidade dos Alimentos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Resíduos de Praguicidas/análise , Praguicidas/análise , Solanum melongena , Verduras/químicaRESUMO
BACKGROUND: Tolfenpyrad and dinotefuran are two representative pesticides used for pest control in tea gardens. Their application may bring about a potential risk to the health of consumers. Therefore, it is essential to investigate the residue behavior, transfer and risk assessment of tolfenpyrad, dinotefuran and metabolites from tea garden to teacup. RESULTS: An effective analytical method was established and validated to simultaneously determine tolfenpyrad, dinotefuran and its metabolites (DN and UF) in tea. The average recoveries of tolfenpyrad, dinotefuran, DN and UF were in the range 72.1-106.3%, with relative standard deviations lower than 11.8%. On the basis of the proposed method, the dissipation of tolfenpyrad and dinotefuran in fresh tea leaves followed first-order kinetics models with half-lives of 4.30-7.33 days and 4.65-5.50 days, respectively. With application amounts of 112.5-168.75 g a.i. ha-1 once or twice, the terminal residues of tolfenpyrad and total dinotefuran in green tea were lower than 19.6 and 7.13 mg kg-1 , respectively, and below their corresponding maximum residue limits . The leaching rates of tolfenpyrad and total dinotefuran during the tea brewing were in the ranges 1.4-2.3% and 93.7-98.1%, respectively. CONCLUSION: Tolfenpyrad and dinotefuran in tea were easily degraded. The RQc and RQa values for tolfenpyrad were 37.6% and 5.4%, which were much higher than for dinotefuran at 24.7% and 0.84%, respectively. The data indicated that there was no significant health risk in tea for consumers at the recommended dosages. The results provide scientific data regarding the reasonable use of tolfenpyrad and dinotefuran aiming to ensure safe tea consuption. © 2021 Society of Chemical Industry.
Assuntos
Camellia sinensis/crescimento & desenvolvimento , Guanidinas/química , Neonicotinoides/química , Nitrocompostos/química , Resíduos de Praguicidas/química , Pirazóis/química , Chá/química , Camellia sinensis/química , Camellia sinensis/metabolismo , Qualidade de Produtos para o Consumidor , Culinária , Contaminação de Alimentos/análise , Guanidinas/metabolismo , Humanos , Cinética , Neonicotinoides/metabolismo , Nitrocompostos/metabolismo , Resíduos de Praguicidas/metabolismo , Folhas de Planta/química , Folhas de Planta/metabolismo , Pirazóis/metabolismo , Medição de Risco , Chá/metabolismoRESUMO
BACKGROUND: Flonicamid and dinotefuran are widely applied to control pests and diseases in various economic crops arousing much public concerns about the potential risk to human health. In this study, the multi-determination and residual behavior of flonicamid-dinotefuran mixture on peach trees were investigated. The chronic risk of long-term dietary intake for Chinese consumers was evaluated. RESULTS: An optimized QuEChERS method combined with ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis for simultaneous determination of flonicamid, dinotefuran and its metabolites was established to analyze the residual dissipation and terminal residues in peach matrices. The results demonstrated that (i) a satisfactory linearity relationship with the detector response and the correlation coefficient R2 > 0.999, the average recoveries of these four analytes ranged from 94 to 108%, the relative standard deviation was between 1.0% and 8.8%, and the limit of the quantitation was 0.02 mg kg-1 ; (ii) the dissipation behaviors of flonicamid and dinotefuran followed with the first-order dynamic kinetics model, and the half-lives were 6.9-12.4 days and 8.1-15.1 days, respectively; (iii) the recommended preharvest interval (PHI) was 21 days, the risk quotient (RQ) values of flonicamid and dinotefuran were 16.6 and 20.7%, respectively, which were significantly less than 100%. CONCLUSION: The established analytical method met the detection requirement in terms of sensitivity, accuracy, and precision. Additionally, the results indicated that the potential dietary intake risk of the flonicamid-dinotefuran mixture on peach trees was negligible. This work can be utilized in the safe and responsible use of flonicamid-dinotefuran mixture and provide guidance for establishing its maximum residue limit (MRL) in China. © 2021 Society of Chemical Industry.
Assuntos
Guanidinas/química , Neonicotinoides/química , Niacinamida/análogos & derivados , Nitrocompostos/química , Resíduos de Praguicidas/química , Prunus persica/química , China , Cromatografia Líquida de Alta Pressão , Qualidade de Produtos para o Consumidor , Ingestão de Alimentos , Inocuidade dos Alimentos , Frutas/química , Frutas/metabolismo , Guanidinas/metabolismo , Humanos , Cinética , Neonicotinoides/metabolismo , Niacinamida/química , Niacinamida/metabolismo , Nitrocompostos/metabolismo , Resíduos de Praguicidas/metabolismo , Prunus persica/metabolismo , Espectrometria de Massas em TandemRESUMO
BACKGROUND: Thiophanate-methyl and its metabolite carbendazim are broad-spectrum fungicides used on many crops. The residues of these chemicals could result in potential environmental and human health problems. Therefore, investigations of the dissipation and residue behaviors of thiophanate-methyl and its metabolite carbendazim on cowpeas and associated dietary risk assessments are essential for the safety of agricultural products. RESULTS: A simple analytical approach using liquid chromatography with tandem mass spectrometry was developed and validated for the determination of thiophanate-methyl and carbendazim concentrations in cowpeas. Good linearity (R2 > 0.998) was obtained, and the recoveries and relative standard deviations were 80.0-104.7% and 1.4-5.2%, respectively. The dissipation rates of thiophanate-methyl, carbendazim and total carbendazim were high (half-lives of 1.61-2.46 days) and varied in the field cowpea samples because of the different weather conditions and planting patterns. Based on the definition of thiophanate-methyl, the terminal residues of total carbendazim in cowpea samples were below the maximum residue limits set by Japan for other legumes. The acute and chronic risk quotients of three analytes were 0.0-27.6% in cowpea samples gathered from all terminal residue treatments, which were below 100%. CONCLUSION: An optimized approach for detecting thiophanate-methyl and carbendazim in cowpeas was applied for the investigation of field-trial samples. The potential acute and chronic dietary risks of thiophanate-methyl, carbendazim and total carbendazim to the health of Chinese consumers were low. These results could guide the safe and proper use of thiophanate-methyl in cowpeas and offer data for the dietary risk assessment of thiophanate-methyl in cowpeas. © 2021 Society of Chemical Industry.
Assuntos
Benzimidazóis/análise , Carbamatos/análise , Contaminação de Alimentos/análise , Fungicidas Industriais/química , Resíduos de Praguicidas/química , Tiofanato/química , Vigna/química , Benzimidazóis/metabolismo , Carbamatos/metabolismo , China , Fungicidas Industriais/metabolismo , Cinética , Resíduos de Praguicidas/metabolismo , Sementes/química , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Tiofanato/metabolismo , Vigna/crescimento & desenvolvimento , Vigna/metabolismoRESUMO
Currently, the standard approach to estimate systemic exposure of workers after contact with dried pesticide residues on crops during re-entry activities relies on using the highest identified dermal absorption value for aqueous spray dilutions. However, recent dermal absorption studies with dried residues and their respective in-use dilutions have shown that this is likely to significantly overestimate their dermal penetration potential and, thus, predicted systemic exposure. The choice of appropriate dose levels for these dermal absorption studies has not been defined. Moreover, actual skin loading during re-entry tasks may differ significantly from that achieved by applying a fixed volume of an aqueous dilution, which is the standard practice in generic dermal absorption studies. To address this, we propose an approach to dose setting for dried residue studies within the current European risk assessment framework. Skin loading for studies can be calculated from the existing exposure algorithms and by taking appropriate body surface areas into account. Thus, skin loading in studies will vary depending on the exact nature and duration of the task and the region of the body exposed, reflecting actual exposure scenarios.
Assuntos
Exposição Ocupacional , Resíduos de Praguicidas , Humanos , Exposição Ocupacional/análise , Resíduos de Praguicidas/análise , Resíduos de Praguicidas/metabolismo , Medição de Risco , Pele/química , Absorção CutâneaRESUMO
BACKGROUND: Boscalid is often used to extend the storage time of postharvest cherry tomato. Pesticide residue has become an issue of food safety. This study sought to investigate the spatial distribution of boscalid residue in cherry tomato fruits and to determine the effect of 24-epibrassinolide (EBR) in promoting boscalid degradation. RESULTS: Boscalid could quickly penetrate into cherry tomatoes, but mainly remained in the peel. The migration of boscalid from the peel into the core was a time-consuming and complex process during storage. After 72 h, boscalid residues in the pulp and the core began to accumulate gradually. The exogenous application of EBR activated peroxidase, glutathione reductase and glutathione S-transferase, and effectively promoted the degradation of boscalid by a maximum decrease of 44.8% in peel, 54.0% in pulp and 71.2% in core. CONCLUSION: As one of the common pesticides, boscalid had a strong ability to enter the cherry tomato and thus become a potential risk for public consumption. Therefore, rational use of pesticides is recommended. The results of this study indicate that the possible risk of boscalid residue could be alleviated by EBR pretreatment through activating detoxification enzymes. © 2020 Society of Chemical Industry.