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1.
Chembiochem ; 25(7): e202300742, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38426686

RESUMO

Pesticides are essential in agricultural development. Controlled-release pesticides have attracted great attentions. Base on a principle of spatiotemporal selectivity, we extended the photoremovable protective group (PRPG) into agrochemical agents to achieve controllable release of active ingredients. Herein, we obtained NP-TBZ by covalently linking o-nitrobenzyl (NP) with thiabendazole (TBZ). Compound NP-TBZ can be controlled to release TBZ in dependent to light. The irradiated and unirradiated NP-TBZ showed significant differences on fungicidal activities both in vitro and in vivo. In addition, the irradiated NP-TBZ displayed similar antifungal activities to the directly-used TBZ, indicating a factual applicability in controllable release of TBZ. Furthermore, we explored the action mode and microcosmic variations by SEM analysis, and demonstrated that the irradiated NP-TBZ retained a same action mode with TBZ against mycelia growth.


Assuntos
Praguicidas , Tiabendazol , Tiabendazol/farmacologia , Tiabendazol/análise , Preparações de Ação Retardada , Antifúngicos/farmacologia
2.
Anal Bioanal Chem ; 416(2): 497-508, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38001372

RESUMO

Pesticides that linger in the environment and ecosystems for an extended period can cause severe and dangerous health problems in humans. To detect pesticides in foods, the development of high-sensitivity and quick screening technologies was required. This research investigated the performance of Au@Ag NPs with varying thicknesses of the silver shell for detecting trace quantities of thiabendazole (TBZ) in apples using surface-enhanced Raman spectroscopy (SERS). The Au@Ag NPs were synthesized by coating 32 nm gold seeds with different thicknesses of silver shell ranging from 2.4 to 8.7 nm, achieved by adjusting the incorporation of AgNO3 and ascorbic acid. The optimized Au@Ag NPs with a 7.3 nm silver shell demonstrated outstanding SERS activity, high sensitivity, and a detection limit of 0.05 µg/mL for TBZ. The R2 values, representing the goodness of fit, were found to be 0.990 and 0.986 for standard and real TBZ samples, respectively, indicating a strong correlation between the measured signal and the TBZ concentration. The recovery analysis showed a reliable and accurate detection capability (96 to 105%), suggesting good reliability and accuracy of the SERS-based detection using the optimal Au@Ag NPs. Overall, this research highlights the potential of SERS with optimal Au@Ag NPs for rapid and effective monitoring of pesticides in the food industry.


Assuntos
Malus , Nanopartículas Metálicas , Praguicidas , Humanos , Malus/química , Tiabendazol/análise , Prata/química , Reprodutibilidade dos Testes , Ecossistema , Nanopartículas Metálicas/química , Análise Espectral Raman/métodos , Praguicidas/análise , Ouro/química
3.
Anal Bioanal Chem ; 416(14): 3295-3303, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38696128

RESUMO

Thiabendazole, a widely used broad-spectrum fungicide in agriculture, poses risks to human health. To monitor its presence in water, we propose a fluorescent aptasensor utilizing Escherichia coli exonuclease I (Exo I). The findings demonstrate a linear correlation between thiabendazole concentrations and digestion percentage, with a detection limit (LOD) exceeding 1 µM and a determination coefficient (R2) of 0.959. This aptamer-based fluorescence spectroscopy detection system holds promise for a rapid, specific, and sensitive analysis of thiabendazole in environmental waters and food matrices.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Limite de Detecção , Espectrometria de Fluorescência , Tiabendazol , Tiabendazol/análise , Aptâmeros de Nucleotídeos/química , Espectrometria de Fluorescência/métodos , Técnicas Biossensoriais/métodos , Fungicidas Industriais/análise , Exodesoxirribonucleases/metabolismo , Exodesoxirribonucleases/química , Escherichia coli , Poluentes Químicos da Água/análise , Corantes Fluorescentes/química
4.
J Sci Food Agric ; 104(5): 2630-2640, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-37985216

RESUMO

BACKGROUND: Understanding the role of adjuvants in pesticide persistence is crucial to develop effective pesticide formulations and manage pesticide residues in fresh produce. This study investigated the impact of a commercial non-ionic surfactant product containing alkylphenol ethoxylates (APEOs) on the persistence of thiabendazole on apple and spinach surfaces against the 30 kg m-3 baking soda (sodium bicarbonate, NaHCO3 ) soaking, which was used to remove the active ingredient (AI) in the cuticular wax layer of fresh produce through alkaline hydrolysis. Surface-enhanced Raman scattering (SERS) mapping method was used to quantify the residue levels on fresh produce surfaces at different experimental scenarios. Four standard curves were established to quantify surface thiabendazole in the absence and presence of APEOs, on apple and spinach leaf surfaces, respectively. RESULTS: Overall, the result showed that APEOs enhanced the persistence of thiabendazole over time. After 3 days of exposure, APEOs increased thiabendazole surface residue against NaHCO3 hydrolysis on apple and spinach surfaces by 5.39% and 10.47%, respectively. CONCLUSION: The study suggests that APEOs led to more pesticide residues on fresh produce and greater difficulty in washing them off from the surfaces using baking soda, posing food safety concerns. © 2023 Society of Chemical Industry.


Assuntos
Malus , Resíduos de Praguicidas , Praguicidas , Malus/química , Resíduos de Praguicidas/análise , Praguicidas/análise , Bicarbonato de Sódio , Análise Espectral Raman/métodos , Spinacia oleracea/química , Tensoativos , Tiabendazol/análise , Fenóis/química
5.
Molecules ; 28(9)2023 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-37175335

RESUMO

Thiabendazole (TBZ) is a fungicide and anthelmintic drug commonly found in food products. Due to its toxicity and potential carcinogenicity, its determination in various samples is important for public health. Different analytical methods can be used to determine the presence and concentration of TBZ in samples. Liquid chromatography (LC) and its subtypes, high-performance liquid chromatography (HPLC) and ultra-high-performance liquid chromatography (UHPLC), are the most commonly used methods for TBZ determination representing 19%, 18%, and 18% of the described methods, respectively. Surface-enhanced Raman spectroscopy (SERS) and fluorimetry are two more methods widely used for TBZ determination, representing 13% and 12% of the described methods, respectively. In this review, a number of methods for TBZ determination are described, but due to their limitations, there is a high potential for the further improvement and development of each method in order to obtain a simple, precise, and accurate method that can be used for routine analysis.


Assuntos
Fungicidas Industriais , Tiabendazol , Tiabendazol/análise , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida/métodos , Fungicidas Industriais/análise , Fluorometria
6.
Sensors (Basel) ; 22(24)2022 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-36560348

RESUMO

Rapid analysis of components in complex matrices has always been a major challenge in constructing sensing methods, especially concerning time and cost. The detection of pesticide residues is an important task in food safety monitoring, which needs efficient methods. Here, we constructed a machine learning-assisted synchronous fluorescence sensing approach for the rapid and simultaneous quantitative detection of two important benzimidazole pesticides, thiabendazole (TBZ) and fuberidazole (FBZ), in red wine. First, fluorescence spectra data were collected using a second derivative constant-energy synchronous fluorescence sensor. Next, we established a prediction model through the machine learning approach. With this approach, the recovery rate of TBZ and FBZ detection of pesticide residues in red wine was 101% ± 5% and 101% ± 15%, respectively, without resorting complicated pretreatment procedures. This work provides a new way for the combination of machine learning and fluorescence techniques to solve the complexity in multi-component analysis in practical applications.


Assuntos
Resíduos de Praguicidas , Vinho , Tiabendazol/análise , Resíduos de Praguicidas/análise , Vinho/análise , Fluorescência , Benzimidazóis
7.
Molecules ; 27(23)2022 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-36500391

RESUMO

During the postharvest period, citrus fruits are exposed to Penicillium italicum, Penicillium digitatum, and Geotrichum candidum. Pesticides such as imazalil (IMZ), thiabendazole (TBZ), orthophenylphenol (OPP), and guazatine (GUA) are commonly used as antifungals. Glyphosate (GP) is also used in citrus fields to eliminate weed growth. The sensitivity of fungal pathogens of citrus fruit to these pesticides and 1,8-cineole was evaluated, and the effect of GP on the development of cross-resistance to other chemicals was monitored over a period of 3 weeks. IMZ most effectively inhibited the mycelial growth and spore germination of P. digitatum and P. italicum, with minimum inhibitory concentrations (MICs) of 0.01 and 0.05 mg/mL, respectively, followed by 1,8-cineole, GP, and TBZ. 1,8-Cineole and GP more effectively inhibited the mycelial growth and spore germination of G. candidum, with minimum inhibitory concentrations (MICs) of 0.2 and 1.0 mg/mL, respectively, than OPP or GUA. For the spore germination assay, all substances tested showed a total inhibitory effect. Subculturing the fungal strains in culture media containing increasing concentrations of GP induced fungal tolerance to GP as well as to the fungicides. In soil, experiments confirmed that GP induced the tolerance of P. digitatum to TBZ and GP and the tolerance of P. italicum to IMZ, TBZ, and GP. However, no tolerance was recorded against 1,8-cineole. In conclusion, it can be said that 1,8-cineole may be recommended as an alternative to conventional fungicides. In addition, these results indicate that caution should be taken when using GP in citrus fields.


Assuntos
Citrus , Fungicidas Industriais , Penicillium , Citrus/química , Eucaliptol/farmacologia , Fungicidas Industriais/farmacologia , Fungicidas Industriais/análise , Tiabendazol/análise , Antifúngicos/farmacologia , Antifúngicos/análise , Frutas/química
8.
Anal Bioanal Chem ; 413(30): 7485-7494, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34642782

RESUMO

Excessive use of pesticides in modern agriculture results in large amounts of pesticide residues in agricultural production, greatly threatening human health. Herein, novel two-dimensional leaf-like zeolitic imidazolate framework-L decorated with multi-walled carbon nanotubes (MWCNTs/ZIF-L) was prepared by a facile solvent way and exploited as electrode material for sensitive electrochemical sensing of thiabendazole (TBZ). Two-dimensional ZIF-L presents high surface area, large pore volume, and abundant active sites, which exhibits high enrichment ability towards TBZ molecules, while the MWCNTs interspersed on ZIF-L can prominently enhance the electron transport capability and improve the electrocatalytic activity for TBZ oxidation. Due to the intriguing synergy between the components, the MWCNTs/ZIF-L-based electrochemical sensor reveals a limit of detection (LOD) of 6.0 nmol·L-1, which is lower than that reported in most literatures. Additionally, satisfactory reproducibility and repeatability, long-term stability, and excellent selectivity are acquired. The proposed method was also applied for the detection of TBZ in apple and orange samples with acceptable recoveries.


Assuntos
Técnicas Eletroquímicas/instrumentação , Estruturas Metalorgânicas/química , Nanotubos de Carbono/química , Resíduos de Praguicidas/análise , Tiabendazol/análise , Eletrodos , Limite de Detecção , Microscopia Eletrônica de Varredura , Reprodutibilidade dos Testes , Zeolitas/química
9.
Anal Bioanal Chem ; 413(16): 4207-4215, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33987702

RESUMO

Accurate and rapid quantitative detection of pesticide and pollutant levels in the actual sample can aid in protecting food security, environmental security, and human health. A high Raman enhancement factor and good repeatability of the surface-enhanced Raman spectroscopy (SERS) substrates are favorable to quantitative analysis. Herein, a quantitative SERS sensor based on constructed self-assembled plasmonic Au@Ag heterogeneous nanocuboids (Au@Ag NCs) monolayer was developed. The sensor was used to quantitatively detect the trace pesticides extracted from pear surfaces and pollutants in fishpond water. Densely packed Au@Ag NCs fabricated into large-scale monolayer films were chemically functionalized using 4-methyl-thiobenzoic acid (4-MBA) at the organic/aqueous interface, in which plentiful nanogaps contribute to increase hotspots. Their sharp corners and edges make the sensor have high SERS performance through providing abundant "hot spots." The obtained optically SERS-based sensor with uniform liquid-state interfacial nanoparticle arrays appeared to have nice SERS performance and uniformity using crystal violet (CV) as a probe molecule. In particular, the proposed SERS sensor was applied for quantitative detection of thiabendazole (TBZ) extracted from pear surfaces and malachite green (MG) in fishpond water down to levels of 0.0105 nM and 0.87 nM for SERS assay respectively. As a result, our proposed SERS quantitative detection strategy is quite preferred to on-site analysis and supervision of contaminant in food samples.


Assuntos
Ouro/química , Nanopartículas Metálicas/química , Praguicidas/análise , Prata/química , Análise Espectral Raman/métodos , Poluentes Químicos da Água/análise , Água Doce/análise , Frutas/química , Nanopartículas Metálicas/ultraestrutura , Pyrus/química , Corantes de Rosanilina/análise , Tiabendazol/análise
10.
Int J Mol Sci ; 22(7)2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33810447

RESUMO

Molecular spectroscopy has been widely used to identify pesticides. The main limitation of this approach is the difficulty of identifying pesticides with similar molecular structures. When these pesticide residues are in trace and mixed states in plants, it poses great challenges for practical identification. This study proposed a state-of-the-art method for the rapid identification of trace (10 mg·L-1) and multiple similar benzimidazole pesticide residues on the surface of Toona sinensis leaves, mainly including benzoyl (BNL), carbendazim (BCM), thiabendazole (TBZ), and their mixtures. The new method combines high-throughput terahertz (THz) imaging technology with a deep learning framework. To further improve the model reliability beyond the THz fingerprint peaks (BNL: 0.70, 1.07, 2.20 THz; BCM: 1.16, 1.35, 2.32 THz; TBZ: 0.92, 1.24, 1.66, 1.95, 2.58 THz), we extracted the absorption spectra in frequencies of 0.2-2.2 THz from images as the input to the deep convolution neural network (DCNN). Compared with fuzzy Sammon clustering and four back-propagation neural network (BPNN) models (TrainCGB, TrainCGF, TrainCGP, and TrainRP), DCNN achieved the highest prediction accuracies of 100%, 94.51%, 96.26%, 94.64%, 98.81%, 94.90%, 96.17%, and 96.99% for the control check group, BNL, BCM, TBZ, BNL + BCM, BNL + TBZ, BCM + TBZ, and BNL + BCM + TBZ, respectively. Taking advantage of THz imaging and DCNN, the image visualization of pesticide distribution and residue types on leaves was realized simultaneously. The results demonstrated that THz imaging and deep learning can be potentially adopted for rapid-sensing detection of trace multi-residues on leaf surfaces, which is of great significance for agriculture and food safety.


Assuntos
Benzimidazóis/farmacologia , Aprendizado Profundo , Resíduos de Praguicidas/análise , Folhas de Planta , Imagem Terahertz/métodos , Toona , Benzimidazóis/análise , Carbamatos/análise , Análise por Conglomerados , Teoria da Densidade Funcional , Inocuidade dos Alimentos , Lógica Fuzzy , Redes Neurais de Computação , Praguicidas , Reprodutibilidade dos Testes , Tiabendazol/análise
11.
Sud Med Ekspert ; 64(3): 34-40, 2021.
Artigo em Russo | MEDLINE | ID: mdl-34013693

RESUMO

OBJECTIVE: Is to study the features and to develop the methods for the determination of thiabendazole in the tissues of cadaveric organs and blood. When performing the experiments the methods of TLC, GC-MS and spectrophotometry were used. The advantages were substantiated and the optimal conditions for the release of thiabendazole from the tissues of organs and blood with acetone were determined. A variant of purification of the substance extracted from biomatrixes by the method of column chromatography of normal pressure (sorbent L 40/100 µm, mobile phase acetone-dichloromethane (9.5: 0.5)) is proposed. To identify the analyte by TLC the Sorbfil plates were used and a toluene-acetonitrile mobile phase (2:8). When identifying thiabendazole by a combination of gas-liquid chromatography and mass spectrometry (fragmentation of molecules by electron impact 70 eV) an HP-5MS column 30 m × 0.25 mm with a non-polar stationary phase (5% -phenyl) -methylpolysiloxane was proposed. The expediency of the spectrophotometric determination of thiabendazole on the basis of absorption in an acetonitrile medium has been shown. Methods for the determination of thiabendazole in tissues of organs and blood have been developed and validated. It is shown that the techniques meet the requirements of linearity, selectivity, correctness, precision and stability. The limits of detection of thiabendazole in the liver and blood are 0.14 and 0.10 mg, respectively; the limits of quantitative determination are 0.26 and 0.18 mg per 100 g of biomatrix.


Assuntos
Materiais Biocompatíveis , Tiabendazol , Cromatografia Líquida de Alta Pressão , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Espectrometria de Massas , Espectrofotometria , Tiabendazol/análise , Tiabendazol/toxicidade
12.
J Sep Sci ; 43(14): 2842-2849, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32320521

RESUMO

In this study, the new and efficient three-dimensional network porous aromatic frameworks materials called Silica-PAFs-a, Florisil-PAFs-a, Silica-PAFs-b, and Florisil-PAFs-b were first synthesized. The properties of materials were analyzed by five characterization methods. The materials were used as adsorbents in pipette-tip solid-phase extraction for the effective determination of carbendazim and thiabendazole in spinach sample. Meanwhile, the obtained materials were tested by static adsorption and dynamic adsorption. The result showed that the specific surface area of materials greatly increased after introducing three-dimensional network porous aromatic frameworks. Microstructural modification exposed a large number of amino reactive groups that made them have a better adsorption amount for the two targets. The calibration graphs of carbendazim and thiabendazole in methanol were linear over 0.10-300.0 µg/mL, and the limits of detection and quantification were 0.00546 and 0.0182 µg/mL, and 0.00741 and 0.0247µg/mL respectively. A reliable analytical method was developed for recognition targets in spinach sample by Silica-PAFs-b with satisfactory extraction recoveries (96.25 and 100.51%). The proposed method using the material was applied for trace analysis of the carbendazim and thiabendazole residue.


Assuntos
Benzimidazóis/análise , Carbamatos/análise , Hidrocarbonetos Aromáticos/química , Spinacia oleracea/química , Tiabendazol/análise , Triazinas/química , Hidrocarbonetos Aromáticos/síntese química , Silicatos de Magnésio/química , Estrutura Molecular , Tamanho da Partícula , Porosidade , Dióxido de Silício/química , Propriedades de Superfície
13.
Anal Chem ; 91(3): 2093-2099, 2019 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-30628431

RESUMO

Understanding the behavior of pesticide translocation is significant for effectively applying pesticides and reducing pesticide exposures from treated plants. Herein, we applied surface enhanced Raman spectroscopy (SERS) for real-time monitoring of pesticide translocation in tomato plant tissues, including leaves and flowers, following root exposure in hydroponic and soil systems. Various concentrations of the systemic pesticide, thiabendazole, was introduced into hydroponic systems used for growing tomato plants. At selected time intervals, tomato leaves and flowers were picked and thiabendazole was measured directly under a Raman microscope after pipetting gold nanoparticle-containing solution onto the plant tissue. We found that the pesticide signals first appeared along the midrib in the lowest leaves and moved distally to the edge of the leaves. As the concentration of pesticide applied to the root was increased, the time necessary to detect the signal was decreased. The SERS surface mapping method was also able to detect thiabendazole in the trichomes of the leaves. In addition, we found a unique SERS peak at 737 cm-1 on both leaves and flowers at 4 and 6 days following the application of 200 mg/L thiabendazole to the hydroponic system. This peak appears to be coming from adenine-containing materials and may be related to the plant's response to pesticide toxicity, which could be used as a potential marker for monitoring plant responses to stresses. These results demonstrate a successful application of SERS as a rapid and effective way to study the real-time translocation behavior of pesticides in a plant system.


Assuntos
Praguicidas/análise , Solanum lycopersicum/química , Tiabendazol/análise , Solanum lycopersicum/metabolismo , Praguicidas/farmacocinética , Análise Espectral Raman , Tiabendazol/farmacocinética , Fatores de Tempo
14.
J Sep Sci ; 42(9): 1786-1793, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30805997

RESUMO

A new sample preparation method based on SBA-15 assisted electromembrane extraction coupled with corona discharge ion mobility spectrometer was developed for the determination of Thiabendazole as a model basic pesticide in fruit juice samples. The addition of SBA-15 in the supported liquid membrane in electromembrane extraction system not only can lead to enhancement of the effective surface area, but also introducing the negatively charged silanol groups into supported liquid membrane might improve migration of positively charged analytes toward the supported liquid membrane and finally into the acceptor solution. To investigate the effect of the presence of SBA-15 in the supported liquid membrane on the extraction efficiency, a comparative study was carried out between the conventional electromembrane extraction and SBA-15/electromembrane extraction methods. Under the optimized conditions, SBA-15/electromembrane extraction method showed higher extraction efficiencies in comparison with conventional electromembrane extraction method. SBA-15/electromembrane extraction method exhibited a low limit of detection (0.9 ng/mL), high preconcentration factor (167) and high recovery (83%). Finally, the applicability of SBA-15/electromembrane extraction method was studied by the extraction and determination of Thiabendazole as a model basic pesticide in fruit juice samples.


Assuntos
Técnicas Eletroquímicas/métodos , Sucos de Frutas e Vegetais/análise , Praguicidas/isolamento & purificação , Tiabendazol/isolamento & purificação , Animais , Técnicas Eletroquímicas/instrumentação , Limite de Detecção , Membranas Artificiais , Praguicidas/análise , Dióxido de Silício/química , Tiabendazol/análise
15.
Anal Bioanal Chem ; 410(26): 6923-6934, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30094787

RESUMO

Fluorescence polarization immunoassays (FPIAs) for thiabendazole and tetraconazole were first developed. Tracers for FPIAs of thiabendazole and tetraconazole were synthesized and the tracers' structures were confirmed by HPLC-MS/MS. The 4-aminomethylfluorescein-labeled tracers allowed achieving the best assay sensitivity and minimum reagent consumption in comparison with aminofluorescein-labeled and alkyldiaminefluoresceinthiocarbamyl-labeled tracers. Measurements of fluorescence polarization were performed using a portable device. The developed FPIA methods were applied for the analysis of wheat. Fast and simple sample preparation technique earlier developed by authors for pesticides was adapted for thiabendazole and tetraconazole. The limits of detection of thiabendazole and tetraconazole in wheat were 20 and 200 µg/kg, and the lower limits of quantification were 40 and 600 µg/kg, respectively. The recovery test was performed by two methods-FPIA and HPLC-MS/MS. The results obtained by FPIA correlated well with those obtained by HPLC-MS/MS (r2 = 0.9985 for thiabendazole, r2 = 0.9952 for tetraconazole). Average recoveries of thiabendazole and tetraconazole were 74 ± 4% and 72 ± 3% by FPIA, and average recoveries of thiabendazole and tetraconazole were 86 ± 2% and 74 ± 1% by HPLC-MS/MS (n = 15). Graphical abstract ᅟ.


Assuntos
Anti-Helmínticos/análise , Clorobenzenos/análise , Imunoensaio de Fluorescência por Polarização/métodos , Fungicidas Industriais/análise , Praguicidas/análise , Tiabendazol/análise , Triazóis/análise , Triticum/química , Cromatografia Líquida de Alta Pressão/métodos , Indicadores e Reagentes/química , Limite de Detecção , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem/métodos
16.
Molecules ; 23(8)2018 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-30081585

RESUMO

Thiabendazole (TBZ) is widely used in sclerotium blight, downy mildew as well as root rot disease prevention and treatment in plant. The indiscriminate use of TBZ causes the excess pesticide residues in soil, which leads to soil hardening and environmental pollution. Therefore, it is important to accurately monitor whether the TBZ residue in soil exceeds the standard. For this study, density functional theory (DFT) was used to theoretically analyze the molecular structure of TBZ, gold nanoparticles (AuNPs) were used to enhance the detection signal of surface-enhanced Raman spectroscopy (SERS) and the TBZ residue in red soil extracts was quantitatively determined by SERS. As a result, the theoretical Raman peaks of TBZ calculated by DFT were basically consistent with the measured results. Moreover, 784, 1008, 1270, 1328, 1406 and 1576 cm-1 could be determined as the TBZ characteristic peaks in soil and the limits of detection (LOD) could reach 0.1 mg/L. Also, there was a good linear correlation between the intensity of Raman peaks and TBZ concentration in soil (784 cm-1: y = 672.26x + 5748.4, R² = 0.9948; 1008 cm-1: y = 1155.4x + 8740.2, R² = 0.9938) and the limit of quantification (LOQ) of these two linear models can reach 1 mg/L. The relative standard deviation (RSD) ranged from 1.36% to 8.02% and the recovery was ranging from 95.90% to 116.65%. In addition, the 300⁻1700 cm-1 SERS of TBZ were analyzed by the partial least squares (PLS) and backward interval partial least squares (biPLS). Also, the prediction accuracy of TBZ in soil (Rp² = 0.9769, RMSEP = 0.556 mg/L, RPD = 5.97) was the highest when the original spectra were pretreated by standard normal variation (SNV) and then modeled by PLS. In summary, the TBZ in red soil extracts could be quantitatively determined by SERS based on AuNPs, which was beneficial to provide a new, rapid and accurate scheme for the detection of pesticide residues in soil.


Assuntos
Nanopartículas Metálicas/química , Solo/química , Análise Espectral Raman/métodos , Tiabendazol/análise , Ouro/química , Resíduos de Praguicidas/análise
17.
Electrophoresis ; 37(19): 2517-2521, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-26990428

RESUMO

A micellar liquid chromatographic method to determine thiabendazole (TBZ) and o-phenylphenol in wastewater is described here. The sample was directly injected without any additional treatment other filtration. The pesticides were resolved in <11 min, using a mobile phase of 0.10 M SDS-6% 1-pentanol buffered at pH 3 running through a C18 column at 1 mL/min. The detection was performed by fluorescence at 305/360 and 245/345 nm excitation/emission wavelengths for TBZ and o-phenylphenol, respectively. The method was validated following the directives of the Validation and Peer Review of U.S. Environmental Protection Agency Chemical Methods of Analysis guidelines in terms of selectivity, quantitation range (0.01-0.02 to 2 mg/L), detection limit (0.005-0.008 mg/L), trueness (92.1-104.2%), precision (<13.9%), robustness (<6.6%), and stability under storage conditions. The procedure was applied to the screening of TBZ and o-phenylphenol in wastewater samples from citrus packing plants, agricultural gutters, urban sewage, as well as in influent and effluent wastewater treatment plants.


Assuntos
Compostos de Bifenilo/análise , Cromatografia Líquida/métodos , Resíduos de Praguicidas/análise , Tiabendazol/análise , Águas Residuárias/química , Poluentes Químicos da Água/análise , Agricultura , Compostos de Bifenilo/química , Compostos de Bifenilo/isolamento & purificação , Citrus , Análise dos Mínimos Quadrados , Limite de Detecção , Micelas , Resíduos de Praguicidas/química , Resíduos de Praguicidas/isolamento & purificação , Reprodutibilidade dos Testes , Espectrometria de Fluorescência , Tiabendazol/química , Tiabendazol/isolamento & purificação , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
18.
Analyst ; 140(5): 1739-46, 2015 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-25604004

RESUMO

A micellar liquid chromatographic method has been developed for the simultaneous quantification of the pesticides thiabendazole and chlorpyrifos, as well as an alkylphenol, which is included in pesticide formulations, i.e., 4-tert-octylphenol, in water. A sample was filtered and directly injected, avoiding large extraction steps using toxic solvents, thus expediting the experimental procedure. The contaminants were eluted without interferences in <17 min, using a mobile phase of 0.15 M sodium dodecyl sulfate ­ 6% 1-pentanol buffered at pH 3, running through a C18 column at 1 mL min(-1) under the isocratic mode. This optimal mobile phase was selected using a statistical approach, which considers the retention factor, efficiency and peak shape of the analytes measured in only a few mobile phases. The detection was carried out by measuring absorbance at 220 nm. The method was successfully validated in terms of specificity, calibration range (0.5-10 mg L(-1)), linearity (r(2) > 0.994), limit of detection and quantification (0.2-0.3; and 0.5-0.8 mg L(-1), respectively), intra- and interday accuracy (95.2-102.9%), precision (<8.3%), and ruggedness (<9.3%). The stability in storage conditions (at least 14 days) was studied. The method was safe, inexpensive, produced little pollutant and has a short analysis time, thus it is useful for the routine analysis of samples. Finally, the method was applied to analyse wastewater from the fruit-processing industry, wastewater treatment plants, and in sewage water belonging to the Castelló area (Spain). The results were similar to those obtained by an already reliable method.


Assuntos
Clorpirifos/análise , Cromatografia Líquida/instrumentação , Cromatografia Líquida/métodos , Fenóis/análise , Tiabendazol/análise , Águas Residuárias/análise , Micelas , Esgotos/análise
19.
Nanotechnology ; 26(1): 015502, 2015 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-25490192

RESUMO

Simple, sensitive, and rapid detection of trace levels of extensively used and highly toxic pesticides are in urgent demand for public health. Surface-enhanced Raman scattering (SERS)-based sensor was designed to achieve ultrasensitive and simple pesticide sensing. We developed a portable sensor system composed of high performance and reliable gold nanofinger sensor strips and a custom-built portable Raman spectrometer. Compared to the general procedure and previously reported studies that are limited to laboratory settings, our analytical method is simple, sensitive, rapid, and cost-effective. Based on the SERS results, the chemical interaction of two pesticides, chlorpyrifos (CPF) and thiabendazole (TBZ), with gold nanofingers was studied to determine a fingerprint for each pesticide. The portable SERS-sensor system was successfully demonstrated to detect CPF and TBZ pesticides within 15 min with a detection limit of 35 ppt in drinking water and 7 ppb on apple skin, respectively.


Assuntos
Nanopartículas Metálicas/química , Nanotecnologia/instrumentação , Praguicidas/análise , Análise Espectral Raman/instrumentação , Clorpirifos/análise , Ouro/química , Humanos , Limite de Detecção , Tiabendazol/análise
20.
Luminescence ; 30(6): 872-7, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25645350

RESUMO

Food safety has become a large concern and prompts an urgent need for the development of rapid, simple and sensitive analytical methods that can monitor pesticide residues in foods. This study aimed to provide a method for quantitative determination of trace thiabendazole in apple juice. Due to its high sensitivity and selectivity, fluorescence spectrophotometry was utilized as a front end to dispersive liquid-liquid microextraction (DLLME). The experimental parameters that influenced the extraction were systematically investigated. Under optimum conditions, the whole procedure, including DLLME and analysis of one sample, was carried out within 5 min, and linearity was found in the 5-50 µg/L range with a correlation coefficient (r) of 0.9987. The limit of detection value was 2.2 µg/L. Good reproducibility was achieved based with a less than 4.5% relative standard deviation (RSD) for five replicates at different sample concentrations. This method was shown to be suitable for rapid and sensitive quantification of thiabendazole in apple juice.


Assuntos
Análise de Alimentos/métodos , Sucos de Frutas e Vegetais/análise , Microextração em Fase Líquida/métodos , Espectrometria de Fluorescência/métodos , Tiabendazol/análise , Contaminação de Alimentos/análise , Concentração de Íons de Hidrogênio , Malus/química , Reprodutibilidade dos Testes , Solventes , Fatores de Tempo
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