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1.
J Agric Food Chem ; 68(6): 1514-1524, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-31977218

RESUMO

Pesticides coated to the seed surface potentially pose an ecological risk to granivorous birds that consume incompletely buried or spilled seeds. To assess the toxicokinetics of seeds treated with current-use fungicides, Japanese quail (Coturnix japonica) were orally dosed with commercially coated wheat seeds. Quail were exposed to metalaxyl, tebuconazole, and fludioxonil at either a low dose (0.0655, 0.0308, and 0.0328 mg/kg of body weight, respectively) or a high dose (0.196, 0.0925, and 0.0985 mg/kg of body weight, respectively). Fungicides were rapidly absorbed and distributed to tissues. Tebuconazole was metabolized into tert-butylhydroxy-tebuconazole. All compounds were eliminated to below detection limits within 24 h. The high detection frequencies observed in fecal samples potentially offer a non-invasive matrix to monitor pesticide exposure. With the summation of total body burden across plasma, tissue, and fecal samples, less than 9% of the administered dose was identified as the parent fungicide, demonstrating the importance to monitor both active ingredients and their metabolites in biological samples.


Assuntos
Coturnix/metabolismo , Fungicidas Industriais/metabolismo , Triazóis/metabolismo , Triticum/metabolismo , Animais , Transporte Biológico , Fezes/química , Fungicidas Industriais/análise , Fungicidas Industriais/toxicidade , Sementes/química , Sementes/metabolismo , Toxicocinética , Triazóis/análise , Triazóis/toxicidade , Triticum/química
2.
Chemosphere ; 242: 125163, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31677518

RESUMO

The use of fungicides bears the risk of many undesirable outcomes that are manifested in, among other things, changes in the structure and activity of microorganisms. This study aimed at determining the effect of a Helicur 250 EW preparation, used to protect crops against fungal diseases, on the microbiological and biochemical activity of soil and on the development of Horderum vulgare L. The fungicide was sprayed on leaves of spring barley in the following doses (per active substance, i.e. tebuconazole, TEB): 0.046, 0.093, 0.139, 1.395, and 2.790 mg TEB plant-1. The following indices were analyzed in the study: index of microorganisms resistance (RS) to the effects of fungicide, microorganisms colony development index (CD), microorganisms ecophysiological diversity index (EP), genetic diversity of bacteria, enzymatic activity, and effect of the fungicide on spring barley development (IFH). The most susceptible to the effects of the fungicide turned out to be fungi. The metagenomic analysis demonstrated that the bacterial community differed in terms of structure and percentage contribution in the soil exposed to the fungicide from the control soil even at the Phylum level. However, Proteobacteria appeared to be the prevailing taxon in both soils. Bacillus arabhattai, B. soli, and B. simplex occurred exclusively in the control soil, whereas Ramlibacter tataounensis, Azospirillum palatum, and Kaistobacter terrae - exclusively in the soil contaminated with the fungicide. Helicur 250 EW suppressed activities of all soil enzymes except for arylsulfatase. In addition, it proved to be a strong inhibitor of spring barley growth and development.


Assuntos
Fungicidas Industriais/toxicidade , Hordeum/crescimento & desenvolvimento , Microbiota/efeitos dos fármacos , Microbiologia do Solo/normas , Poluentes do Solo/toxicidade , Triazóis/toxicidade , Bactérias/efeitos dos fármacos , Bactérias/enzimologia , Fungos/efeitos dos fármacos , Fungos/enzimologia , Fungicidas Industriais/análise , Metagenoma/efeitos dos fármacos , Microbiota/genética , Folhas de Planta/crescimento & desenvolvimento , Solo/química , Poluentes do Solo/análise , Triazóis/análise
3.
Biomed Chromatogr ; 34(1): e4694, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31465553

RESUMO

A simple and rapid analytical method for the detection of trifloxystrobin, trifloxystrobin acid and tebuconazole in soil, brown rice, paddy plants and rice hulls was established and validated by liquid chromatography with tandem mass spectrometry. Acceptable linearity (R2 > 0.99), accuracy (average recoveries of 74.3-108.5%) and precision (intra- and inter-day relative standard deviations of 0.9-8.8%) were obtained using the developed determination approach. In the field trial, the half-lives of trifloxystrobin and tebuconazole in paddy plants were 5.7-8.3 days in three locations throughout China, and the terminal residue concentrations of trifloxystrobin and tebuconazole were <100 and 500 µg/kg (maximum residue limits set by China), respectively, at harvest, which indicated that, based on the recommended application procedure, trifloxystrobin and tebuconazole are safe for use on rice. The risk assessment results demonstrated that, owing to risk quotient values of both fungicides being <100%, the potential risk of trifloxystrobin and tebuconazole on rice was acceptable for Chinese consumers. These data could provide supporting information for the proper use and safety evaluation of trifloxystrobin and tebuconazole in rice.


Assuntos
Acetatos/análise , Fungicidas Industriais/análise , Iminas/análise , Oryza/química , Resíduos de Praguicidas/análise , Estrobilurinas/análise , Triazóis/análise , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Limite de Detecção , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Medição de Risco , Solo/química , Adulto Jovem
4.
J Sci Food Agric ; 100(5): 1980-1989, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31849062

RESUMO

BACKGROUND: In this study, an infrared-based prediction method was developed for easy, fast and non-destructive detection of pesticide residue levels measured by reference analysis in strawberry (Fragaria × ananassa Duch, cv. Albion) samples using near-infrared spectroscopy and demonstrating its potential alternative or complementary use instead of traditional pesticide determination methods. Strawberries of Albion variety, which were supplied directly from greenhouses, were used as the study material. A total of 60 batch sample groups, each consisting of eight strawberries, was formed, and each group was treated with a commercial pesticide at different concentrations (26.7% boscalid + 6.7% pyraclostrobin) and varying residual levels were obtained in strawberry batches. The strawberry samples with pesticide residuals were used both to collect near-infrared spectra and to determine reference pesticide levels, applying QuEChERS (quick, easy, cheap, rugged, safe) extraction, followed by liquid chromatographic-mass spectrometric analysis. RESULTS AND CONCLUSION: Partial least squares regression (PLSR) models were developed for boscalid and pyraclostrobin active substances. During model development, the samples were randomly divided into two groups as calibration (n = 48) and validation (n = 12) sets. A calibration model was developed for each active substance, and then the models were validated using cross-validation and external sets. Performance evaluation of the PLSR models was evaluated based on the residual predictive deviation (RPD) of each model. An RPD of 2.28 was obtained for boscalid, while it was 2.31 for pyraclostrobin. These results indicate that the developed models have reasonable predictive power. © 2019 Society of Chemical Industry.


Assuntos
Contaminação de Alimentos/análise , Fragaria/química , Resíduos de Praguicidas/análise , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Compostos de Bifenilo/análise , Frutas/química , Fungicidas Industriais/análise , Análise dos Mínimos Quadrados , Niacinamida/análogos & derivados , Niacinamida/análise , Estrobilurinas/análise
5.
Food Chem ; 309: 125691, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31679853

RESUMO

This study presented a HPTLC platformed luminescent biosensor system for screening captan residue. First, the potential bio-effects of layers materials on the detectability of a luminescent bacteria Photobacterium phosphoreum (ATCC 11040) as the sensor cell were assessed. From comparison, it was noteworthy that the combination of sensor cells with normal silica gel layer exclusively gave outstanding detectability (<10 ng/zone). On this basis, HPTLC mediated separation and biosensing was further optimized. Then, the obtained graphic results were digitally quantified via software processing, offering satisfactory selectivity, linearity (R2 = 0.9901 within 10-80 ng/zone) and sensitivity (0.5 mg/kg against MRLs ≥ 6 mg/kg). Additionally, the performance of the established method was validated with different fruits (recover rates 75-96%, RSD < 11.8%). Meanwhile, it was demonstrated that detectability of this hybrid system would be tuneable by altering the combination of bacteria strains and layer materials, which was meaningful to strengthen the usability of microbial biosensors.


Assuntos
Técnicas Biossensoriais/métodos , Captana/análise , Fungicidas Industriais/análise , Cromatografia em Camada Delgada , Frutas/química , Frutas/metabolismo , Malus/química , Malus/metabolismo , Photobacterium/química , Photobacterium/isolamento & purificação , Sílica Gel/química
6.
Environ Sci Pollut Res Int ; 26(35): 35924-35934, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31707613

RESUMO

This study aimed to investigate changes in metalaxyl-M sorption-desorption capacity of soil following the addition of two types of amendments. Two biochars (BC) from grapevine pruning residues (BC-G) and spruce wood (BC-S) and two vermicomposts (VC) obtained vermicomposting digestates from a mixture of manure and olive mill wastewater (VC-M) and buffalo manure (VC-B) were used. Using a batch equilibration method, the materials and a silt loam soil non-amended or amended with each material at 2% (w/w) were interacted with the fungicide at a concentration of 2 mg L-1 for kinetics study and in the range 1-20 mg L-1 for sorption isotherms. Kinetics results showed that metalaxyl-M onto the amendments and non-amended soil followed preferentially a pseudo-second-order model, thus indicating a chemisorption process. Sorption isotherm data of the product on BC and VC fitted well the Freundlich equation, whereas those on non-amended and amended soil followed preferentially a linear model. The KFads values were 995.2, 788.5, 55.2, 52.1, 6.4, 6.0, 3.4, 2.6 and 1.5 L kg-1 for BC-G, BC-S, VC-M, VC-B, soil-BC-G, soil-BC-S, soil-VC-M, soil-VC-B and non-amended soil, respectively. Product desorption from each soil sample occurred to a lesser extent than sorption. Highly significant correlations (P < 0.005) were found between the values of sorption and desorption constants of all adsorbents and organic C content, thus confirming the prominent role of organic matter in the sorption process of metalaxyl-M.


Assuntos
Alanina/análogos & derivados , Carvão Vegetal/química , Fungicidas Industriais/química , Poluentes do Solo/química , Adsorção , Alanina/análise , Alanina/química , Fungicidas Industriais/análise , Esterco , Olea , Solo/química , Poluentes do Solo/análise , Madeira/química
7.
J Agric Food Chem ; 67(46): 12904-12910, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31657925

RESUMO

In this study, a rapid, sensitive, and selective method was established for the detection of oxathiapiprolin and the metabolite IN-E8S72, as well as its glucose conjugate IN-SXS67 in cucumber using modified QuEChERS procedure combined with HPLC-MS/MS. The LOQs for all compounds were 0.02 mg kg-1, and the average recoveries were 77.4-111.3% with RSDs of 1.0-8.5%. Under the optimized conditions, the established method was successfully used to determine field samples in dissipation and terminal residue studies. The dissipation study results showed that oxathiapiprolin dissipated rapidly in cucumber with half-lives of 2.4-4.0 days. On the basis of the terminal residue results, the risk assessment was conducted, and both the international estimated daily intake (IEDI) or national estimated daily intake (NEDI) of oxathiapiprolin were much less than 100% which indicate a low health risk to consumers. This work provides guidance for establishing MRL of oxathiapiprolin in China and is of great significance for evaluating its dietary risk in cucumber.


Assuntos
Cucumis sativus/química , Fungicidas Industriais/análise , Hidrocarbonetos Fluorados/análise , Resíduos de Praguicidas/análise , Pirazóis/análise , China , Cromatografia Líquida de Alta Pressão , Qualidade de Produtos para o Consumidor , Cucumis sativus/metabolismo , Contaminação de Alimentos/análise , Fungicidas Industriais/metabolismo , Fungicidas Industriais/toxicidade , Humanos , Hidrocarbonetos Fluorados/metabolismo , Hidrocarbonetos Fluorados/toxicidade , Resíduos de Praguicidas/metabolismo , Resíduos de Praguicidas/toxicidade , Pirazóis/metabolismo , Pirazóis/toxicidade , Medição de Risco , Espectrometria de Massas em Tandem
8.
Environ Monit Assess ; 191(11): 670, 2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31650309

RESUMO

An analytical method involving modified QuEChERS (quick, easy, cheap, effective, rugged and safe) technique coupled with LC-MS/MS (liquid chromatography-tandem mass spectroscopy) has been developed for simultaneous identification and quantification of 71 pesticides (insecticides/acaricides/nematicides (32), fungicides (12), herbicides (26), plant growth regulator (1)) in different pulses (edible seeds of leguminous plants), namely gram, lentil, black gram and pea. The analysis was done using Shimadzu LC-MS/MS-8030 instrument equipped with Zorbax Eclipse Plus C-18 column operating under electrospray ionization (ESI) in positive and negative modes. Validation of method was done as per a single laboratory validation approach. Nine-point linear calibration curves for each pesticide were obtained in the range of 0.005 to 2 µg/g with correlation coefficient of ≥ 0.98. Limit of detection (LOD) for all the pesticides was achieved in the range of 0.001-0.015 µg/g, whereas the limit of quantification (LOQ) were found in the range of 0.01-0.05 µg/g. Recovery studies were conducted at 0.01- and 0.05-µg/g level of fortification using modified buffered QuEChERS method standardized for low moisture foods. It was observed that due to matrix interference, only around 75% of the pesticides were recovered in an acceptable range of 70-120% when compared against the solvent standard. With matrix-matched standards, 95% of the recovery results came within acceptable range with highly acceptable HorRat ratio (between 0.2 and 0.8) indicating satisfactory precision. The global and expanded uncertainties for estimation of each pesticide in above-mentioned pulse matrices were calculated to evaluate the suitability of the developed method for quantification of pesticides in pulse matrices.


Assuntos
Monitoramento Ambiental/métodos , Fungicidas Industriais/análise , Herbicidas/análise , Inseticidas/análise , Resíduos de Praguicidas/análise , Verduras/química , Cromatografia Líquida/métodos , Proteção de Cultivos , Limite de Detecção , Sementes/química , Espectrometria de Massas em Tandem/métodos
9.
Environ Monit Assess ; 191(11): 644, 2019 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-31606848

RESUMO

The bayberry is an important economic fruit as well as a minor crop in China, and few pesticide products are registered for bayberry. Prochloraz is a widely used fungicide with a high detection rate on bayberry. This study evaluated the potential dietary risk of prochloraz for different populations in China based on field trial data and market surveillance. The results indicate that one-time applications at dosages of 1000 and 1500 mg/kg with a recommended preharvest interval of 20 days do not pose a chronic or acute dietary risk. However, applying the above dosages twice will cause a potential short-term dietary risk. Risk assessment results conducted on surveillance samples indicated acceptable long-term risks for the general population, with a hazard quotient < 0.82. Furthermore, simulated washing and wine production processes were performed to mimic household practices to investigate residue transfer and distribution. We found that rinsing with tap water for 1 min was an effective way to remove residue, and the processing factors of prochloraz for both bayberry and wine were < 1, indicating that wine production could reduce residue levels. Prochloraz had a strong capacity to transfer to wine due to its high log Kow value, with transfer percentages up to 43%. This study supports the recommendation on good agricultural practices for prochloraz application and provides a guide for safe consumption.


Assuntos
Exposição Dietética/análise , Frutas/química , Fungicidas Industriais/análise , Imidazóis/análise , Myrica/química , Resíduos de Praguicidas/análise , Vinho/análise , China , Dieta , Medição de Risco
10.
Ecotoxicol Environ Saf ; 186: 109783, 2019 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-31629192

RESUMO

Chemical fungicides are effective tools in controlling plant pathogens; however, these chemicals can, on the other hand, distress the ecosystem. Accordingly, the current research investigates the potentiality of substituting traditional chemical fungicides by inducing plant resistance against infection with soil-born pathogens i.e. Sclerotium rolfsii in the presence of mycorrhizae (AMF) as plant inoculants and one of the following amendments: humic acid, sulphex (a mixture of canola oil and diluted sulphuric acid) and paclobutrazol (ABZ). To attain the abovementioned objective, a field (mildly infected with S. rolfsii) was cultivated with Helianthus tuberosus (a perennial plant belongs to the Asteraceae family) for two successive seasons (2014 and 2015) and the above-mentioned treatments were tested for their feasibilities in controlling S. rolfsii infection against the chemical fungicide "Vitavax-200" either solely or in combinations in a complete randomized block design. Inoculating plants with AMF or amending soils with either humic acid, Sulphex or ABZ solely increased significantly the activities of plant defense enzymes by approximately 1.5-2.1 folds higher than the control treatment. These treatments also improved NPK availability in soil and; hence, increased their contents within plant tubers. Consequently, these treatments decreased the disease incidence and severity caused by S. rolfsii while improved shoot biomass and tuber yield. In spite of that, these results stood below the prospective of the fungicide treatment. The integrated treatments i.e. "humic acid + AMF", "Sulphex + AMF" and "ABZ + AMF" caused further significant improvements in both NPK availabilities in soil and plant areal bio-masses. This probably induced further plant resistance against the investigated soil-borne pathogen while recorded insignificant variations in disease incidence and severity when compared with the fungicide treatment. Moreover, the integrated treatments increased the tuber yields beyond those attained for the fungicide treatment. Accordingly, such integrated strategies can completely substitute the chemical fungicides; thus, minimize their negative impacts on the ecosystem.


Assuntos
Basidiomycota/fisiologia , Resistência à Doença/fisiologia , Recuperação e Remediação Ambiental/métodos , Helianthus/microbiologia , Micorrizas/fisiologia , Microbiologia do Solo , Biomassa , Fungicidas Industriais/análise , Helianthus/metabolismo , Helianthus/fisiologia , Nutrientes/análise , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Distribuição Aleatória , Solo/química
11.
Artigo em Inglês | MEDLINE | ID: mdl-31599694

RESUMO

Ochratoxin A (OTA) is a secondary metabolite produced by filamentous fungi species belonging to the genera Penicillium and Aspergillus. The contamination of grapes by ochratoxigenic species occurs worldwide in regions of tropical and temperate climates. Better control of fungal growth is achieved through good cultural practice and proper selection of fungicides. Kresoxim-methyl and famoxadone are the most common fungicides used in vineyards. This study aimed at analysing the OTA production and toxigenic potential of Aspergillus carbonarius under fungicide treatment with famoxadone and kresoxim-methyl. The growth rate of A. carbonarius was evaluated by measuring the glucosamine content and the diameter of the fungal colonies. OTA production was quantified by HPLC analysis. The treatment with fungicides, kresoxim-methyl and famoxadone, significantly reduced the fungal growth, by 76% and 60%, respectively. However, the mycotoxin production was greater in the fungicide-treated groups than the control group, showing that even though the fungicides were effective in controlling fungal growth, they were ineffective against mycotoxin production.


Assuntos
Aspergillus/efeitos dos fármacos , Fungicidas Industriais/toxicidade , Estrobilurinas/toxicidade , Aspergillus/crescimento & desenvolvimento , Contaminação de Alimentos/análise , Fungicidas Industriais/análise , Estrobilurinas/análise
12.
Environ Monit Assess ; 191(10): 628, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31502086

RESUMO

The present study was done to assess the dissipation behavior, decontamination, and half-life time of ready-mix formulation of trifloxystrobin (25% w/w) and tebuconazole (50% w/w) in okra and soil under the crop after foliar spray at fruiting stage. Samples of okra and soil were collected periodically, i.e., zero (2 h after spray), 1, 3, 5, 7, 10, 15, 20, and 25 days after third application at a 7-day interval. Residues of these fungicides were determined by gas liquid chromatography (GLC) equipped with electron capture detector (ECD) and gas chromatography-tandem mass spectrometry (GCMS-triple quadruple). The limits of quantification (LOQ) and detection (LOD) for both the fungicides were 0.01 and 0.003 mg kg-1, respectively. Washing alone with faucet water was found successful in minimizing the residues. Soil was free from residual contamination at fifth day after spraying in case of both the fungicides and at both the doses.


Assuntos
Abelmoschus/metabolismo , Acetatos/metabolismo , Fungicidas Industriais/metabolismo , Iminas/metabolismo , Resíduos de Praguicidas/análise , Solo/química , Estrobilurinas/metabolismo , Triazóis/metabolismo , Abelmoschus/química , Acetatos/análise , Descontaminação , Monitoramento Ambiental , Frutas/química , Frutas/metabolismo , Fungicidas Industriais/análise , Meia-Vida , Iminas/análise , Estrobilurinas/análise , Triazóis/análise
13.
Regul Toxicol Pharmacol ; 108: 104471, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31493441

RESUMO

Multi-locational supervised field trials were conducted in different agro-climatic regions in India to study dissipation of trifloxystrobin and tebuconazole in tomato after spraying a combination formulation (trifloxystrobin 25% + tebuconazole 50%, 75WG) at recommended doses: (i) single (trifloxystrobin 87.5 g a.i. ha-1 + tebuconazole 175 g a.i. ha-1) and (ii) double (trifloxystrobin 175 g a.i. ha-1 + tebuconazole 350 g a.i. ha-1). Fruit samples were extracted with ethyl acetate using a modified QuEChERS method. The residues (parent fungicides + metabolite) were analyzed and confirmed by GC-ECD and GC-MS, respectively. The half-life (t1/2) of trifloxystrobin and tebuconazole in tomato varied from 1.08 to 1.72 and 1.13 -to 1.64 days at single; and 1.27 to 2.13 and 1.24 to 1.96 days at double dose, respectively. Since maximum residue limit (MRL) at pre-harvest interval (PHI) of 5 days is impractical, as tomato is usually harvested and consumed almost everyday after the last spray, the risk assessment was performed at minimum PHI of 1 day. Accordingly, on the basis of supervised field trial data and using OECD MRL calculator, MRL of 0.5 and 1.5 mg kg-1 at single dose were proposed for trifloxystrobin and tebuconazole in/on tomato, respectively.


Assuntos
Acetatos/análise , Frutas/química , Fungicidas Industriais/análise , Iminas/análise , Lycopersicon esculentum , Resíduos de Praguicidas/análise , Estrobilurinas/análise , Triazóis/análise , Adulto , Criança , Exposição Dietética , Cromatografia Gasosa-Espectrometria de Massas , Meia-Vida , Humanos , Nível de Efeito Adverso não Observado , Medição de Risco
14.
Food Chem ; 301: 125265, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31387046

RESUMO

A novel method for determination of triazole fungicides and their enantiomers in foods was developed by aqueous two-phase extraction (ATPE) coupled with two-dimensional liquid chromatography (2D-LC). With an aqueous two-phase system (ATPS) of ethanol/K2HPO4 as biphasic extractant, the effects of the ATPS composition, extraction temperature and time on extraction yields of triazole fungicides were investigated. Optimum conditions were concluded as follows: ethanol concentration 31% (w/w) and K2HPO4 concentration 21% (w/w), extraction temperature 60 °C, extraction time 21 min. Based on reversed-phase separation systems, a 2D-LC was constructed by optimizing chromatographic conditions and online heart-cutting procedures. As a result, eight triazole fungicides and their enantiomers were separated respectively on C18 and cellulose-tris (3,5-dimethylphenylcarbamate) stationary phases, revealing good linear relationship in the range of 0.1218-30.06 µg/mL (R2 ≥ 0.9984). The detection limits and recoveries were 0.03113-0.3525 µg/mL and 71.57-107.8%, respectively. The ATPE-2D-LC method was successfully applied to chiral analysis of triazole fungicides in fruits and vegetables.


Assuntos
Cromatografia Líquida/métodos , Frutas/química , Fungicidas Industriais/análise , Extração Líquido-Líquido/métodos , Triazóis/análise , Verduras/química , Fungicidas Industriais/química , Fungicidas Industriais/isolamento & purificação , Limite de Detecção , Estereoisomerismo , Triazóis/química , Triazóis/isolamento & purificação
15.
Regul Toxicol Pharmacol ; 108: 104447, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31430505

RESUMO

The dissipation kinetics, residue levels, and potential risks of diflubenzuron and difenoconazole on peaches were investigated under open field conditions. Two years of field trials were carried out in Shanghai, China, and the half-lives of diflubenzuron and difenoconazole on peaches ranged from 4.4 to 25d. Their terminal residue concentrations on peaches were 0.022-5.7 mg/kg after three of the tested sampling intervals. Based on the maximum residue levels (MRLs) of difenoconazole on peaches, a preharvest interval (PHI) of 14 d was proposed. A PHI of 10 d was proposed for diflubenzuron after a dietary safety assessment. During the safety assessment, the hazard quotient (HQ) and risk quotient (RQ) on peaches were determined. The results showed that the HQs (3.6-8.3%) and RQs(51-55%) of diflubenzuron were acceptable, proving that diflubenzuron poses no potential health risks. For difenoconazole, the HQs (0.027-0.071%) were satisfactory, but the RQs (115-116%) exceeded 100%, which indicated potential risk.


Assuntos
Diflubenzuron/análise , Dioxolanos/análise , Frutas/química , Fungicidas Industriais/análise , Resíduos de Praguicidas/análise , Prunus persica , Triazóis/análise , Exposição Dietética/análise , Monitoramento Ambiental , Contaminação de Alimentos/análise , Humanos , Medição de Risco
16.
Biomed Chromatogr ; 33(12): e4688, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31445506

RESUMO

Phenamacril is a new broad-spectrum fungicide that is commonly used for the control of fungal diseases in wheat and rice. In this study, ultra-high-performance liquid chromatography-tandem mass spectrometry was used to establish a method for analyzing the residual phenamacril in flour and rice based on the improved QuEChERS (quick, easy, cheap, effective, rugged and safe) method using Z-Sep+ as the adsorbent in the pre-treatment process. The average recovery of phenamacril in flour and rice was 82.2-96.0%, the relative standard deviation was 2.1-5.6% and the limit of quantification was 0.5 µg/kg. The accuracy and sensitivity of this method meet the requirements for residue analysis. The method was applied to commercially available flour and rice samples, and the detected concentrations of phenamacril were 0.005-0.033 mg/kg. This method provides technical support for the safety evaluation of phenamacril.


Assuntos
Cianoacrilatos/análise , Farinha/análise , Fungicidas Industriais/análise , Oryza/química , Resíduos de Praguicidas/análise , Cromatografia Líquida de Alta Pressão/métodos , Modelos Lineares , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria de Massas em Tandem/métodos
17.
Ecotoxicol Environ Saf ; 183: 109546, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31437727

RESUMO

A ß-cyclodextrin-functionalized magnetic zinc-metal organic framework (M-MOF/ß-CD) was synthesized via a facile one-pot reaction. M-MOF/ß-CD was used as a magnetic porous absorbent for the extraction and determination of prochloraz and three triazole fungicides in vegetable samples. M-MOF/ß-CD was prepared by creating MOF layers on the surface of a Fe3O4-graphene oxide (GO) nanocomposite and bonding them with ß-CD molecules. Characterization suggested that a 3D porous structure was formed, with M-MOF/ß-CD exhibiting high superparamagnetism and a large surface area. As a new strategy, integrating MOFs with Fe3O4-GO could improve their water-resistance and mechanical strength by providing a rigid nanosupport interface. Combining M-MOF and ß-CD resulted in excellent selective adsorption capacities for prochloraz and three triazole fungicides. The static adsorption process was evaluated and the results were in good agreement with the Freundlich model. Subsequently, M-MOF/ß-CD was applied to extracting prochloraz and triazole fungicides from tomato and lettuce vegetables, followed by HPLC-MS/MS determination. The limits of detection for the above fungicides were found to be 0.25-1.0 µg/L at a signal-to-noise ratio of 3, with spiked recoveries of 74.13%-119.83%, indicating that M-MOF/ß-CD was promising for application to the extraction and determination of fungicides in complex matrices.


Assuntos
Fungicidas Industriais/análise , Imidazóis/análise , Nanopartículas de Magnetita/química , Estruturas Metalorgânicas/química , Triazóis/análise , Verduras/química , beta-Ciclodextrinas/química , Adsorção , Grafite/química , Limite de Detecção , Nanocompostos/química , Porosidade , Reprodutibilidade dos Testes , Propriedades de Superfície
18.
J Environ Sci Health B ; 54(12): 942-947, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31407614

RESUMO

The effect of fenhexamid, mepanipyrim and cyazofamid fungicides on in vitro bioavailability of antioxidant activity and phenolic compounds of Tempranillo and Graciano red wine was studied by simulating the digestive process by dialysis in semipermeable membranes. Determination of antioxidant activity was through reaction with the DPPH • radical and the measurement of phenolic compounds was made with liquid chromatography with diode detector (HPLC-DAD). Fenhexamid, mepanipyrim and cyazofamid reduce the total polyphenol content in both wines. During dialysis there was a large loss of total polyphenols (80-90%) and of antioxidant activity (> 90%). The bioavailability of the phenolic compounds is lower than that for non-treated wines and the highest dialization percentages were found for stilbenes > 50%. While for the remaining phenolic fraction the order is the following hydroxycinnamic derivatives > anthocyanins > flavonols.


Assuntos
Antioxidantes/análise , Resíduos de Drogas/análise , Fungicidas Industriais/análise , Trato Gastrointestinal/metabolismo , Fenóis/análise , Vinho/análise , Antocianinas/análise , Antioxidantes/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Digestão , Fungicidas Industriais/metabolismo , Humanos , Fenóis/metabolismo , Polifenóis/análise , Polifenóis/metabolismo
19.
Regul Toxicol Pharmacol ; 108: 104450, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31449917

RESUMO

The dissipation rates of pyraclostrobin, a methoxyacrylate strobilurin group fungicide, along with its final residues and dietary exposure in strawberry were studied under Egyptian field conditions. Extraction was performed using a QuEChERS method, while residue determination was performed using liquid chromatography tandem mass spectrometry (LC-MS/MS) with limits of quantitation of 0.001 mgkg-1. At three different fortification levels (1.0, 10 and 100 ng/g) of pyraclostrobin applied to untreated strawberry samples, the recoveries ranged between 97 and 104% with relative standard deviation (RSD) of 1-6% (n = 6). The reported analytical method fulfills the standard requirements with regard to specificity, repeatability, limit of quantitation and recoveries. The half-life (t1/2) of pyraclostrobin after one single application of the recommended rate was 5 days. Risk assessment study was carried out by comparing the national estimated daily intake (NEDI) against acceptable daily intake (ADI) under good agricultural practice (GAP) conditions. Results indicated that strawberry treated with pyraclostrobin at the recommended dosage, are safe for human consumption three days after two successive applications with 14 days interval between each application. The present research should pave the way for the establishment of the safe and proper use of pyraclostrobin in strawberry in Egypt.


Assuntos
Exposição Dietética/análise , Contaminação de Alimentos/análise , Fragaria , Frutas/química , Fungicidas Industriais/análise , Resíduos de Praguicidas/análise , Estrobilurinas/análise , Adulto , Cromatografia Líquida , Egito , Meia-Vida , Humanos , Medição de Risco , Espectrometria de Massas em Tandem
20.
Environ Int ; 131: 104965, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31284112

RESUMO

The use of pesticides to ensure global food security is the most important pest control strategy in modern agriculture but causes extensive soil pollution. This pollution involves potential risks to human health and ecosystems. In addition to soil animal growth, the adverse impact of pesticides on the gut microbiomes of nontarget soil fauna remains largely unknown. Here, the effect of the fungicide azoxystrobin (AZ) on soil and the gut microbiota of soil animals (Enchytraeus crypticus) was studied. The tested concentrations of AZ altered the bacterial community in the soil and E. crypticus gut and were slightly toxic with respect to E. crypticus adult mortality and reproduction. The most abundant bacterial phylum, Proteobacteria, significantly increased in response to the 2 and 5 mg/kg AZ treatments, which implied a disordered unhealthy gut bacterial community. Furthermore, bacterial community analysis between the soil and gut showed that the main effect of AZ on the gut microbiota was directly through AZ, not soil microbiota. In addition, AZ exposure significantly enhanced the number and total abundance of antibiotic resistance genes (ARGs) in the E. crypticus gut; these genes may enter the soil food web to affect higher trophic levels and cause a more serious ecological risk. Our study reported the effect of pesticides on the gut of soil animals and on the enrichment of ARGs as global emerging contaminants, revealing unknown potential impacts of fungicides on ecosystem services and sustainable food production.


Assuntos
Bactérias/efeitos dos fármacos , Fungicidas Industriais/toxicidade , Microbioma Gastrointestinal/efeitos dos fármacos , Oligoquetos/microbiologia , Pirimidinas/toxicidade , Estrobilurinas/toxicidade , Animais , Farmacorresistência Bacteriana Múltipla , Fungicidas Industriais/análise , Solo , Poluentes do Solo/análise
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