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1.
Analyst ; 149(14): 3765-3772, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38842353

RESUMO

Molecularly imprinted polymer (MIP)-based chromatographic separation materials, owing to their advantages of unique selectivity, low cost, suitable reproducibility, and acceptable stability, have attracted a great deal of research in different fields. In this investigation, a new type of MIP-coated silica (MIP/SiO2) separation material was developed using sulfamethoxazole as a template; the specific recognition ability of MIP and appropriate physicochemical properties (abundant Si-OH, suitable pore structure, good stability, etc.) of SiO2 microbeads were combined. The MIP/SiO2 separation materials were characterized carefully. Then, various compounds (such as sulfonamides, ginsenosides, nucleosides, and several pesticides) were used to comprehensively evaluate the chromatographic performances of the MIP/SiO2 column. Furthermore, the chromatographic performances of the MIP/SiO2 column were compared with those of other separation materials (such as non-imprinted polymer-coated silica, C18/SiO2, and bare silica) packed columns. The resolution value of all measured compounds was more than 1.51. The column efficiencies of 13 510 plates per meter (N m-1) for sulfamethoxazole, 11 600 N m-1 for ginsenoside Rd, and 10 510 N m-1 for 2'-deoxyadenosine were obtained. The acceptable results verified that the MIP/SiO2 column can be applied to separate highly polar drugs such as sulfonamides, ginsenosides, nucleosides, and pesticides.


Assuntos
Microesferas , Polímeros Molecularmente Impressos , Dióxido de Silício , Dióxido de Silício/química , Cromatografia Líquida de Alta Pressão/métodos , Polímeros Molecularmente Impressos/química , Ginsenosídeos/química , Ginsenosídeos/análise , Ginsenosídeos/isolamento & purificação , Impressão Molecular/métodos , Nucleosídeos/química , Nucleosídeos/isolamento & purificação , Nucleosídeos/análise , Praguicidas/análise , Praguicidas/química , Praguicidas/isolamento & purificação , Polímeros/química
2.
Inorg Chem ; 63(33): 15311-15322, 2024 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-39115455

RESUMO

The widespread use and contamination of natural sources by new-generation drugs and pesticides have enhanced concern about environmental pollution. Understanding the above importance, we developed a superhydrophobic metal-organic framework (MOF) (SHMOF': [Zr6O4(OH)4(BDC-NH-CO-R)2.4(BDC-NH2)0.6(CF3COO)6]·2.5H2O·4DMF) for ecological remediation via adsorption-based separation of hydrophobic drugs (flurbiprofen) and pesticides (fluazinam). The newly developed SHMOF' has a high adsorption capacity toward flurbiprofen and fluazinam, i.e., 435 and 575 mg/g, respectively. The adsorption equilibrium time of the MOF is very short (15 and 10 min for flurbiprofen and fluazinam, respectively). The outstanding superhydrophobic nature of the MOF was employed to separate flurbiprofen and fluazinam from highly alkaline and acidic media and environmental water samples. The SHMOF' has excellent selectivity toward the adsorption-based separation of flurbiprofen and fluazinam in the coexistence of common analytes. Again, we developed a polypropylene (PP) fabric-based composite of SHMOF' (SHMOF'@PP) to separate the hydrophobic targeted analytes by using a zero-energy-consuming filtration-based separation method, which made this separation process cost-efficient and user-friendly. Moreover, Ag nanoparticles were doped to the superhydrophobic composite. The Ag-doped reusable SHMOF'@PP@Ag composite exhibited excellent bacterial antiadhesion and antibacterial properties toward Staphylococcus aureus bacteria.


Assuntos
Antibacterianos , Interações Hidrofóbicas e Hidrofílicas , Estruturas Metalorgânicas , Praguicidas , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/isolamento & purificação , Praguicidas/isolamento & purificação , Praguicidas/química , Praguicidas/farmacologia , Adsorção , Staphylococcus aureus/efeitos dos fármacos , Poluentes Químicos da Água/isolamento & purificação , Poluentes Químicos da Água/química , Testes de Sensibilidade Microbiana , Propriedades de Superfície , Flurbiprofeno/química , Flurbiprofeno/farmacologia , Flurbiprofeno/isolamento & purificação , Estrutura Molecular
3.
Molecules ; 29(14)2024 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-39065001

RESUMO

A deep eutectic solvent (DES) with the ability to change from hydrophilic to hydrophobic was designed and synthesized and applied to the determination of organophosphorus (OPP) pesticides in honeysuckle dew samples. Choline chloride, phenol, and tetrahydrofuran (THF) were used as the hydrogen bond acceptor, hydrogen bond donor, and demulsifier, respectively. Eight OPP pesticides were extracted by DES coupled with ultrasonic-assisted extraction (UA) and then chromatographed by GC-MS. DES used as an extract solvent has the advantages of high extraction efficiency, low cost, and environmental protection. Furthermore, DES is compatible with GC-MS. The single factor experiment design and Box-Behnken design (BBD) were applied to the optimization of experimental factors, including the type and composition of extraction solvent, type of demulsifier solvent, the volume of DES and THF, pH of sample solution, and ultrasonic time. Under the optimum experimental conditions, the high degree of linearity from 0.1 to 20.0 ng mL-1 (R2 ≥ 0.9989), the limits of detection from 0.014 to 0.051 ng mL-1 (S/N = 3), and the recoveries of analytes from 81.4 to 104.4% with relative standard deviation below 8.6%. In addition, the adsorption mechanism of OPPs on DES was explored by adsorption kinetic studies. These results have demonstrated that the present method has offered an effective, accurate, and sensitive methodology for OPP pesticides in honeysuckle dew samples, and this method provides a reference for the detection of pesticide residues in traditional Chinese medicine.


Assuntos
Solventes Eutéticos Profundos , Microextração em Fase Líquida , Compostos Organofosforados , Praguicidas , Microextração em Fase Líquida/métodos , Praguicidas/análise , Praguicidas/isolamento & purificação , Praguicidas/química , Compostos Organofosforados/análise , Compostos Organofosforados/química , Solventes Eutéticos Profundos/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Lonicera/química , Solventes/química , Ondas Ultrassônicas , Limite de Detecção
4.
Molecules ; 29(11)2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38893504

RESUMO

The chemical industry explosion in the 20th century has led to increased environmental pollution, affecting fauna, flora, and waterways. These substances alter water's taste, color, and smell, making it unfit for consumption or toxic. Agricultural water networks face threats from pollution before and after treatment. Some chemical contaminants, like pesticides, are embedded in natural biogeochemical cycles. In this study, we developed a simple and low-cost procedure for the fabrication of needles coated with polydimethylsiloxane (PDMS) as an efficient sorbent for the microextraction of organic pollutant traces from water. The prepared needles were used as an alternative for commercial solid-phase micro-extraction (SPME) devices in analytical chemistry. The PDMS polymeric phase was characterized by Fourier-transform infrared spectroscopy (FT-IR), thermogravimetry (TGA), and scanning electron microscopy (SEM). The PDMS-coated needles were used for extraction of thirteen pesticides by direct-immersion solid-phase microextraction (DI-SPME) from contaminated waters, followed by determination with gas chromatography-mass spectrometry (GC-MS). The developed analytical method showed limits of detection (LODs) between 0.3 and 2.5 ng mL-1 and RSDs in the range of 0.8-12.2%. The homemade needles were applied for the extraction of pesticides in surface and ground aqueous samples collected from an agricultural area. Several target pesticides were identified and quantified in the investigated water samples.


Assuntos
Praguicidas , Microextração em Fase Sólida , Poluentes Químicos da Água , Microextração em Fase Sólida/métodos , Praguicidas/análise , Praguicidas/isolamento & purificação , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas/métodos , Agricultura , Dimetilpolisiloxanos/química , Água/química , Espectroscopia de Infravermelho com Transformada de Fourier , Limite de Detecção , Agulhas
5.
Molecules ; 29(10)2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38792172

RESUMO

Pyrethroid pesticides (PYRs) have found widespread application in agriculture for the protection of fruit and vegetable crops. Nonetheless, excessive usage or improper application may allow the residues to exceed the safe limits and pose a threat to consumer safety. Thus, there is an urgent need to develop efficient technologies for the elimination or trace detection of PYRs from vegetables. Here, a simple and efficient magnetic solid-phase extraction (MSPE) strategy was developed for the simultaneous purification and enrichment of five PYRs in vegetables, employing the magnetic covalent organic framework nanomaterial COF-SiO2@Fe3O4 as an adsorbent. COF-SiO2@Fe3O4 was prepared by a straightforward solvothermal method, using Fe3O4 as a magnetic core and benzidine and 3,3,5,5-tetraaldehyde biphenyl as the two building units. COF-SiO2@Fe3O4 could effectively capture the targeted PYRs by virtue of its abundant π-electron system and hydroxyl groups. The impact of various experimental parameters on the extraction efficiency was investigated to optimize the MSPE conditions, including the adsorbent amount, extraction time, elution solvent type and elution time. Subsequently, method validation was conducted under the optimal conditions in conjunction with gas chromatography-mass spectrometry (GC-MS). Within the range of 5.00-100 µg·kg-1 (1.00-100 µg·kg-1 for bifenthrin and 2.5-100 µg·kg-1 for fenpropathrin), the five PYRs exhibited a strong linear relationship, with determination coefficients ranging from 0.9990 to 0.9997. The limits of detection (LODs) were 0.3-1.5 µg·kg-1, and the limits of quantification (LOQs) were 0.9-4.5 µg·kg-1. The recoveries were 80.2-116.7% with relative standard deviations (RSDs) below 7.0%. Finally, COF-SiO2@Fe3O4, NH2-SiO2@Fe3O4 and Fe3O4 were compared as MSPE adsorbents for PYRs. The results indicated that COF-SiO2@Fe3O4 was an efficient and rapid selective adsorbent for PYRs. This method holds promise for the determination of PYRs in real samples.


Assuntos
Praguicidas , Piretrinas , Dióxido de Silício , Extração em Fase Sólida , Verduras , Extração em Fase Sólida/métodos , Dióxido de Silício/química , Verduras/química , Piretrinas/isolamento & purificação , Piretrinas/análise , Piretrinas/química , Praguicidas/isolamento & purificação , Praguicidas/química , Praguicidas/análise , Cromatografia Gasosa-Espectrometria de Massas , Adsorção , Contaminação de Alimentos/análise , Limite de Detecção , Resíduos de Praguicidas/análise , Resíduos de Praguicidas/isolamento & purificação , Compostos Férricos/química , Cobalto
6.
Chem Biodivers ; 19(1): e202100560, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34793626

RESUMO

The objective of this research was to evaluate the contamination of pesticides of carbamate and benzimidazole classes in soil, water and soybean seeds, incorrectly discarded near a spring in the state of Goiás-Brazil. The Solid-Liquid and Liquid-Liquid Extraction with Low Temperature Partition (SLE/LTP or LLE/LTP) methods were used for pesticide extraction and the analyses were performed by HPLC-UV. A high resolution mass spectrometer was used to confirm the identity of the compounds present in the seeds. The results showed that the soybeans were treated with the pesticide carbendazim and the dosage was three times higher than established by Brazilian legislation. In the soil and water analyzed there was no presence of the pesticides researched, nor of the carbendazim detected in the seeds. Since this was an environmental crime due to incorrect disposal, it is not known how long ago it occurred. Thus, depending on how long the seeds had been exposed there, the pesticide could have leached out, and caused contamination in the spring and soil. Thus, we conclude that the incorrect disposal of seeds treated with pesticides can be a risk to the permanence of life on the site.


Assuntos
Glycine max/química , Praguicidas/análise , Brasil , Cromatografia Líquida de Alta Pressão , Extração Líquido-Líquido , Praguicidas/isolamento & purificação , Rios/química , Sementes/química , Sementes/metabolismo , Poluentes do Solo/análise , Extração em Fase Sólida , Glycine max/metabolismo , Espectrometria de Massas por Ionização por Electrospray
7.
Electrophoresis ; 42(3): 219-232, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33215711

RESUMO

Natural product analysis has gained wide attention in recent years, especially for herbal medicines, which contain complex ingredients and play a significant clinical role in the therapy of numerous diseases. The constituents of natural products are usually found at low concentrations, and the matrices are complex. Thus, the extraction of target compounds from natural products before analysis by analytical instruments is very significant for human health and its wide application. The commonly used traditional extraction methods are time-consuming, using large amounts of sample and organic solvents, as well as expensive and inefficient. Recently, microextraction techniques have been used for natural product extraction to overcome the disadvantages of conventional extraction methods. In this paper, the successful applications of and recent developments in microextraction techniques including solvent-based and sorbent-based microextraction methods, in natural product analysis in recent years, especially in the last 5 years, are reviewed for the first time. Their features, advantages, disadvantages, and future development trends are also discussed.


Assuntos
Microextração em Fase Líquida , Microextração em Fase Sólida , Alcaloides/análise , Alcaloides/química , Alcaloides/isolamento & purificação , Produtos Biológicos/análise , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Praguicidas/análise , Praguicidas/química , Praguicidas/isolamento & purificação , Solventes/química
8.
Int J Mol Sci ; 22(16)2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34445079

RESUMO

Solid-phase extraction (SPE) coupled to LC/MS/MS analysis is a valid approach for the determination of organic micropollutants (OMPs) in liquid samples. To remove the greatest number of OMPs from environmental matrices, the development of innovative sorbent materials is crucial. Recently, much attention has been paid to inorganic nanosystems such as graphite-derived materials. Graphene oxide has been employed in water-purification processes, including the removal of several micropollutants such as dyes, flame retardants, or pharmaceutical products. Polysaccharides have also been widely used as convenient media for the dispersion of sorbent materials, thanks to their unique properties such as biodegradability, biocompatibility, nontoxicity, and low cost. In this work, chitosan-graphene oxide (CS_GO) composite membranes containing different amounts of GO were prepared and used as sorbents for the SPE of pesticides. To improve their dimensional stability in aqueous medium, the CS_GO membranes were surface crosslinked with glutaraldehyde. The composite systems were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, swelling degree, contact angle, and mechanical measurements. As the GO content increased, a decrease in surface homogeneity, an improvement of mechanical properties, and a reduction of thermal stability of the CS-based membranes were observed. The increased dimensional stability in water, together with the presence of high GO amounts, made the prepared composite membranes more efficacious than the ones based just on CS in isolating and preconcentrating different hydrophilic/hydrophobic pollutants.


Assuntos
Quitosana/química , Grafite/química , Membranas Artificiais , Praguicidas/isolamento & purificação , Extração em Fase Sólida/instrumentação , Poluentes Químicos da Água/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Praguicidas/análise , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem , Água/análise , Poluentes Químicos da Água/análise
9.
Molecules ; 26(4)2021 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-33669919

RESUMO

With the rapid development of global industry and increasingly frequent product circulation, the separation and detection of chiral drugs/pesticides are becoming increasingly important. The chiral nature of substances can result in harm to the human body, and the selective endocrine-disrupting effect of drug enantiomers is caused by differential enantiospecific binding to receptors. This review is devoted to the specific recognition and resolution of chiral molecules by chromatography and membrane-based enantioseparation techniques. Chromatographic enantiomer separations with chiral stationary phase (CSP)-based columns and membrane-based enantiomer filtration are detailed. In addition, the unique properties of these chiral resolution methods have been summarized for practical applications in the chemistry, environment, biology, medicine, and food industries. We further discussed the recognition mechanism in analytical enantioseparations and analyzed recent developments and future prospects of chromatographic and membrane-based enantioseparations.


Assuntos
Praguicidas/isolamento & purificação , Preparações Farmacêuticas/isolamento & purificação , Fracionamento Químico , Cromatografia , Praguicidas/química , Preparações Farmacêuticas/química , Estereoisomerismo
10.
Molecules ; 26(14)2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34299560

RESUMO

Environmental pollutants, such as mycotoxins, pesticides, and pharmaceuticals, are a group of contaminates that occur naturally, while others are produced from anthropogenic sources. With increased research on the adverse ecological and human health effects of these pollutants, there is an increasing need to regularly monitor their levels in food and the environment in order to ensure food safety and public health. The application of magnetic nanomaterials in the analyses of these pollutants could be promising and offers numerous advantages relative to conventional techniques. Due to their ability for the selective adsorption, and ease of separation as a result of magnetic susceptibility, surface modification, stability, cost-effectiveness, availability, and biodegradability, these unique magnetic nanomaterials exhibit great achievement in the improvement of the extraction of different analytes in food. On the other hand, conventional methods involve longer extraction procedures and utilize large quantities of environmentally unfriendly organic solvents. This review centers its attention on current applications of magnetic nanomaterials and their modifications in the extraction of pollutants in food commodities.


Assuntos
Imãs/química , Micotoxinas/isolamento & purificação , Nanoestruturas/química , Praguicidas/isolamento & purificação , Preparações Farmacêuticas/isolamento & purificação , Extração em Fase Sólida/métodos , Animais , Poluentes Ambientais/análise , Poluentes Ambientais/isolamento & purificação , Contaminação de Alimentos/análise , Inocuidade dos Alimentos , Humanos , Micotoxinas/análise , Praguicidas/análise , Preparações Farmacêuticas/análise , Extração em Fase Sólida/instrumentação
11.
Molecules ; 26(5)2021 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-33800794

RESUMO

Pesticides are widely used in agriculture to increase and protect crop production. A substantial percentage of the active substances applied is retained in the soil or flows into water courses, constituting a very relevant environmental problem. There are several methods for the removal of pesticides from soils and water; however, their efficiency is still a challenge. An alternative to current methods relies on the use of effective adsorbents in removing pesticides which are, simultaneously, capable of releasing pesticides into the soil when needed. This reduces costs related to their application and waste treatments and, thus, overall environmental costs. In this paper, we describe the synthesis and preparation of activated carbon-containing poly(ß-cyclodextrin) composites. The composites were characterized by different techniques and their ability to absorb pesticides was assessed by using two active substances: cymoxanil and imidacloprid. Composites with 5 and 10 wt% of activated carbon showed very good stability, high removal efficiencies (>75%) and pesticide sorption capacity up to ca. 50 mg g-1. The effect of additives (NaCl and urea) was also evaluated. The composites were able to release around 30% of the initial sorbed amount of pesticide without losing the capacity to keep the maximum removal efficiency in sorption/desorption cycles.


Assuntos
Carvão Vegetal/química , Géis/química , Praguicidas/análise , Praguicidas/isolamento & purificação , Propilenoglicóis/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/isolamento & purificação , beta-Ciclodextrinas/química
12.
J Environ Sci Health B ; 56(5): 431-438, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33760695

RESUMO

The objective of this study consists of being able to develop a precise, reliable, easy, cheap and quick method to identify and quantify the presence of pesticide metabolites and their parents in human urine. In order to reach our purpose we selected the pesticides and their metabolites with intended uses on permanent crops such as orchards and vineyard. The activity planning started with the identification of the target list carried out by UHPLC-MS/MS and GC-MS/MS, succeeded by several tests oriented to determine the best sample treatment having recourse to instrumental analysis in the range 5-100 ng/mL. Several purifications were also investigated combining different adsorbents (PSA, EMR-lipid and final polish pouch). The use of formic acid during the extraction step has no impact on the recoveries, whereas the PSA adsorbent in the cleanup step negatively affects the results for all investigated metabolites. Any substantial differences were not observed in urine matrix for parent compounds achieving recoveries higher than 80% and RSD less than 20%. The final polish in combination or not with Enhanced Matrix Removal EMR-lipid did not show statistically significant difference in term of trueness and precision for both metabolites and parents, as evaluated by one-way ANOVA. The 3-OH THPI was the most critical compound with not acceptable results for linearity, trueness and precision.


Assuntos
Poluentes Ambientais/urina , Espectrometria de Massas , Praguicidas/urina , Exposição Ambiental/análise , Poluentes Ambientais/isolamento & purificação , Humanos , Espectrometria de Massas/métodos , Resíduos de Praguicidas/isolamento & purificação , Resíduos de Praguicidas/urina , Praguicidas/isolamento & purificação
13.
Anal Chem ; 92(5): 4137-4145, 2020 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-32027489

RESUMO

A total of 15 representative organophosphorus pesticides (OPPs), a class of water pollutants causing serious global concerns, have been sensitively quantified by internal extractive electrospray ionization mass spectrometry (iEESI-MS) after enrichment with Fe3O4-ZrO2 innovatively synthesized in our lab by a one step coprecipitation method. For the premium enrichment, the amounts of Fe3O4-ZrO2, pH value, adsorption time, type and volume of desorption solvent, and shaking time of desorption were systematically optimized. Under optimized conditions, the proposed method provided low limits of detection (LODs) of 0.14-16.39 ng L-1 with relative standard deviations (RSDs) of less than 8.7%. A wide linear response range of about 4 orders of magnitude was achieved with linear coefficients (R2) of 0.9921-0.9999 for all the analytes tested. The present method also provided good recoveries (85.4-105.9%) with acceptable precision (RSDs < 7.2%) in spiked environmental water samples. Furthermore, multiple analytes including dimethoate, omethoate, etc. were simultaneously detected in a single sample run, which was accomplished within 1 min, resulting in significantly improved analytical throughput for quantitative analysis of bulk amounts of samples. The experimental results demonstrated that Fe3O4-ZrO2-iEESI-MS provided advantages, including high sensitivity, high speed, and reasonable selectivity for the detection of OPPs, showing potential applications in environmental water sample analysis and environmental science.


Assuntos
Magnetismo , Nanocompostos/química , Praguicidas/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Poluentes Químicos da Água/análise , Zircônio/química , Óxido Ferroso-Férrico/química , Água Doce/análise , Concentração de Íons de Hidrogênio , Limite de Detecção , Compostos Organofosforados/análise , Compostos Organofosforados/isolamento & purificação , Praguicidas/isolamento & purificação , Extração em Fase Sólida , Poluentes Químicos da Água/isolamento & purificação
14.
Microbiology (Reading) ; 166(11): 1019-1024, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33108264

RESUMO

A formylglycine-generating enzyme (FGE)-sulfatase-based whole-cell biosensor was genetically improved into a single-copy system by integrating the Sinorhizobium meliloti transcriptional activator ChpR and the chpA promoter-FGE-sulfatase fusion into the Escherichia coli chromosome. The sensitivity was further enhanced through a random mutagenesis of the chpR. The new integrated biosensor offered both a lower detection limit [5 nM chlorpyrifos (CPF)] and fluorescence background. The ready-to-use kit was developed using silica gel for on-field detection. The biosensor kit was stable for 20 days when stored at 4 °C. Moreover, a 1-(1-naphthylmethyl)-piperazine (NMP) efflux pump inhibitor can improve the sensitivity by 57 %.


Assuntos
Técnicas Biossensoriais/métodos , Clorpirifos/isolamento & purificação , Praguicidas/isolamento & purificação , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Evolução Molecular Direcionada , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/metabolismo , Glicina/análogos & derivados , Glicina/metabolismo , Limite de Detecção , Piperazinas/farmacologia , Regiões Promotoras Genéticas , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Sinorhizobium meliloti/genética , Sulfatases/genética , Sulfatases/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
15.
Crit Rev Food Sci Nutr ; 60(9): 1581-1592, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-30924347

RESUMO

Food contaminants are challenging the food industry due to the inefficiency of conventional decontamination techniques. Cold plasma as an emerging technique for the degradation of food contaminants attracted notable attention. The current study overviews the plasma-induced degradation of food contaminants, discusses the mechanisms involved, points its benefits and drawbacks out, highlights the research needed in this area, and explores future trends. According to the literature, cold plasma efficiently degraded many common pesticides (e.g. parathion, paraoxon, omethoate, dichlorvos, malathion, azoxystrobin, cyprodinil, fludioxonil, cypermethrin, and chlorpyrifos) and food allergens (e.g. tropomyosin, b-conglycinin, glycinin, trypsin inhibitor, and Kunitztype trypsin inhibitor). These degradations occurred primarily due to the presence of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in the plasma that attack the chemical bonds of food contaminants. The type of pesticide degrades are highly dependent on the concentrations of plasma-generated ROS and RNS. Research showed that several parameters, such as plasma generation device, plasma exposure time, plasma power, and the carrier gas composition, influence the type and concentration of reactive species (e.g. ROS and RNS) and the overall efficiency of cold plasma degradation for a specific pesticide or allergen.HighlightsCold plasma can be used for degradation of many types of pesticides and allergens.Plasma-generated reactive species and UV can interact with pesticides and allergens.The scaled up removal of pesticides and allergens by plasma can be challenging.


Assuntos
Descontaminação/métodos , Contaminação de Alimentos/análise , Indústria Alimentícia/métodos , Gases em Plasma/química , Alérgenos/química , Alérgenos/isolamento & purificação , Praguicidas/química , Praguicidas/isolamento & purificação
16.
Bioorg Chem ; 94: 103439, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31776033

RESUMO

To develop new potential pesticides, a series of matrine-cholesterol derivatives were prepared by modifications of two non-food bioactive products matrine and cholesterol. Two N-phenylsulfonylmatrinic esters (5i and 5j) showed the most potent insecticidal activity against Mythimna separata Walker. Two N-benzylmatrinic esters (5e and 5g) exhibited the most promising aphicidal activity against Aphis citricola Van der Goot. Especially compound 5e showed good control effects in the greenhouse against A. citricola. Some interesting results of their structure-activity relationships were also observed. By reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time polymerase chain reaction (qRT-PCR) analysis of HMG-CoA reductase in apterous adults of A. citricola, it demonstrated that matrine and cholesterol may be the HMG-CoA reductase inhibitors, and the hydroxyl of cholesterol or the lactam ring of matrine may be important for acting with HMG-CoA reductase in A. citricola.


Assuntos
Alcaloides/farmacologia , Afídeos/efeitos dos fármacos , Colesterol/farmacologia , Inibidores Enzimáticos/farmacologia , Mariposas/efeitos dos fármacos , Praguicidas/farmacologia , Quinolizinas/farmacologia , Alcaloides/química , Alcaloides/isolamento & purificação , Animais , Afídeos/enzimologia , Colesterol/química , Colesterol/isolamento & purificação , Relação Dose-Resposta a Droga , Medicamentos de Ervas Chinesas/química , Inibidores Enzimáticos/química , Hidroximetilglutaril-CoA Redutases/metabolismo , Estrutura Molecular , Praguicidas/química , Praguicidas/isolamento & purificação , Quinolizinas/química , Quinolizinas/isolamento & purificação , Relação Estrutura-Atividade , Matrinas
17.
J Sep Sci ; 43(8): 1523-1530, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31989753

RESUMO

A new version of magnetic solid-phase extraction performed in a narrow-bore tube has been proposed for the extraction and preconcentration of different pesticides from various vegetable and fruit juices followed by gas chromatography. A few milligrams of C8 @SiO2 @Fe3 O4 nanoparticles are added into an aqueous sample solution placed in a narrow-bore tube. The sorbent particles move down through the tube under gravity and are collected at the end of the tube by applying an external magnetic field. The end of the tube is narrower and it is connected to a stopcock. After a predetermined time, the stopcock is opened and the solution is passed through the bed of the sorbent maintained by the magnet. Then the adsorbed analytes are desorbed using an elution solvent. To achieve high enrichment factors, a dispersive liquid-liquid microextraction method is carried out. The nanoparticles were characterized by scanning electron microscopy, X-ray diffraction, and FTIR spectroscopy. Under the optimum extraction conditions, limits of detection and quantification were in the ranges of 0.1-0.3 and 0.3-0.9 µg/L, respectively. High enrichment factors (1166-1605) and good extraction recoveries (58-80%) were obtained.


Assuntos
Sucos de Frutas e Vegetais/análise , Praguicidas/isolamento & purificação , Extração em Fase Sólida , Carbono/química , Campos Magnéticos , Nanopartículas de Magnetita/química , Praguicidas/química , Dióxido de Silício/química
18.
J Sep Sci ; 43(6): 1119-1127, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31876075

RESUMO

A stir bar sorptive extraction method coupled with deep eutectic solvent based solidification of floating organic droplets-dispersive liquid-liquid microextraction has been used for the simultaneous derivatization and extraction of some acidic pesticides in tomato samples. In this method, initially the analytes are adsorbed on a coated stir bar from tomato juice filled in a narrow tube. After extraction, the stir bar is removed and a water-miscible deep eutectic solvent is used to elute the analytes. Afterward, a derivatization agent and a water-immiscible deep eutectic solvent (as an extraction solvent) with melting point near to room temperature are added to the obtained eluant at µL-levels and the obtained mixture is rapidly injected into deionized water. Under the optimum conditions, the introduced method indicated high enhancement (1543-3353) and enrichment (2530-2999) factors, low limits of detection (7-14 ng/L) and quantification (23-47 ng/L), good linearity (r2 ≥ 0.9982), and satisfactory repeatabilities (relative standard deviation ≤12% for intra- and inter-day precisions at a concentration of 100 ng/L of each analyte). Finally, the proposed method was applied in analysis of the analytes in tomato samples.


Assuntos
Contaminação de Alimentos/análise , Sucos de Frutas e Vegetais/análise , Microextração em Fase Líquida , Praguicidas/isolamento & purificação , Solanum lycopersicum/química , Adsorção , Concentração de Íons de Hidrogênio , Tamanho da Partícula , Praguicidas/química , Solventes/química , Propriedades de Superfície
19.
J Sep Sci ; 43(4): 756-765, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31722132

RESUMO

Three types of molecularly imprinted solid-phase microextraction fibers were fabricated through sol-gel method using diazinon, parathion-methyl, and isocarbophos as templates, respectively, and assembled together to construct a multifiber for analysis of organophosphorus pesticides in complex matrices. The multifiber provided large extraction capacity and high imprinting factor up to 3.89. In contrast, the imprinting factor of a single fiber was around 1.6, and the multi-template imprinted coating showed no selectivity. The multifiber was applied to analyze pesticides in fruits and vegetables. The limits of detection, which ranged from 0.0052 to 0.23 µg/kg, were lower than those obtained by a single molecularly imprinted fiber, and much lower than those reported by other methods. The recoveries of five analytes in spiked apple, cucumber, Chinese cabbage, and cherry tomato samples were 75.1-123.2%. The study shows that the molecularly imprinted multifiber could achieve simultaneous selective extraction and sensitive determination of multiple targets in complex matrices for high-throughput analysis.


Assuntos
Compostos Organofosforados/isolamento & purificação , Praguicidas/isolamento & purificação , Microextração em Fase Sólida/métodos , Contaminação de Alimentos/análise , Frutas/química , Limite de Detecção , Impressão Molecular , Compostos Organofosforados/química , Praguicidas/química , Polímeros/síntese química , Polímeros/química , Microextração em Fase Sólida/instrumentação , Verduras/química
20.
J Sep Sci ; 43(11): 2115-2124, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32115813

RESUMO

This study describes the synthesis and application of a magnetic amino-functionalized hollow silica-titania microsphere as a new sorbent for magnetic dispersive micro-solid phase extraction of selected pesticides in coffee bean samples. The sorbent was fully characterized by Fourier-transform infrared spectroscopy, field emission scanning electron microscopy, transition electron microscopy, energy-dispersive X-ray spectroscopy, and vibrating sample magnetometry techniques. Significant extraction parameters affecting the proposed method, such as extraction time, sorbent amount, sample solution pH, salt amount, and desorption conditions (desorption solvent and time) were investigated and optimized. All the figures of merits were validated in coffee bean samples under the matrix-matched calibration method. Linear dynamic ranges were 5-250 µg/kg with the determination coefficients (R2 ) > 0.9980. The limits of detection for the pesticides of chlorpyrifos, malathion, hexaconazole, and atrazine were 1.42, 1.43, 1.35, and 1.33 µg/kg, respectively. Finally, the method was successfully applied for the determination of the pesticides in green and roasted coffee bean samples, and the obtained recoveries were in the range of 74-113% for spiked samples. The prepared sorbent could be used for the magnetic dispersive micro-solid phase extraction of pesticides in the plant-derived food matrix.


Assuntos
Café/química , Microesferas , Praguicidas/isolamento & purificação , Dióxido de Silício/química , Titânio/química , Adsorção , Atrazina/química , Atrazina/isolamento & purificação , Clorpirifos/química , Clorpirifos/isolamento & purificação , Fenômenos Magnéticos , Malation/química , Malation/isolamento & purificação , Tamanho da Partícula , Praguicidas/química , Porosidade , Propriedades de Superfície , Triazóis/química , Triazóis/isolamento & purificação
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