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Chemosphere Aug 2010Mutagenic and genotoxic effects of metolcarb were investigated by both bacterial reverse mutation assay in Salmonella typhimurium TA97, TA98, TA100 and TA102 strains...
Mutagenic and genotoxic effects of metolcarb were investigated by both bacterial reverse mutation assay in Salmonella typhimurium TA97, TA98, TA100 and TA102 strains with or without metabolic activation system (S9) and Allium cepa root meristematic cells, respectively. Metolcarb was dissolved in DMSO in Ames/Salmonella test system. 0.1, 1 and 10 microg/plate doses of metolcarb were found to be mutagenic S. typhimurium TA98 without S9. In Allium root growth inhibition test, EC50 value was determined 200 ppm and 0.5xEC50, EC50 and 2xEC50 concentrations of metolcarb were introduced to onion tuber roots and distilled water used as a negative control. Mitotic index (MI), increased in all concentrations compared to control at each exposure time. While disturbed anaphase-telophase, chromosome laggards, stickiness and bridges were observed in anaphase-telophase cells, pro-metaphase, C-mitosis, polyploidy, binuclear cells and disturbed nucleus were observed in other cells. The results were also analyzed statistically by using SPSS for Windows, Mann-Whitney test and Duncan's multiple range tests were performed respectively.
Topics: Anaphase; Environmental Exposure; Mitosis; Mutagenicity Tests; Mutagens; Onions; Phenylcarbamates; Plant Roots; Polyploidy; Salmonella typhimurium; Telophase; Time Factors; Water Pollutants, Chemical
PubMed: 20605189
DOI: 10.1016/j.chemosphere.2010.05.011 -
Journal of AOAC International 2013A novel and fast competitive direct biomimetic ELISA (cd-BELISA) was developed for determination of the N-methylcarbamate insecticide metolcarb based on a molecularly...
Rapid determination of metolcarb residues in foods using a biomimetic enzyme-linked immunosorbent assay employing a novel molecularly imprinted polymer film as artificial antibody.
A novel and fast competitive direct biomimetic ELISA (cd-BELISA) was developed for determination of the N-methylcarbamate insecticide metolcarb based on a molecularly imprinted polymer (MIP) film as the antibody mimic. The MIP film was directly synthesized on the surface of a 96-well plate by bulk polymerization. The synthesized film was characterized, and the results showed that the imprinted film exhibited antibody-antigen-like binding properties and rapid adsorption ability, which was particularly useful for cd-BELISA development. The cd-BELISA conditions were optimized in detail. Under the optimum conditions, the sensitivity and LOD of the cd-BELISA were found to be 17 and 0.12 microg/L, respectively. Crossreactivity demonstrated that the cd-BELISA had a higher selectivity for metolcarb than for structurally related compounds. The developed method was applied to the determination of metolcarb in spiked apple juice, cabbage, and cucumber, with mean recoveries ranging from 71.5 to 117.0%. Validation of the results was conducted by HPLC with good correlation (r2 > 0.9562) between data obtained using these two methods. Therefore, the developed cd-BELISA has potential for the rapid determination of metolcarb in foods.
Topics: Antibodies; Enzyme-Linked Immunosorbent Assay; Food Contamination; Membranes, Artificial; Molecular Structure; Pesticide Residues; Pesticides; Phenylcarbamates; Polymers; Time Factors
PubMed: 23767373
DOI: 10.5740/jaoacint.10-387 -
Food Additives & Contaminants. Part A,... Mar 2010A direct competitive enzyme-linked immunosorbent assay (ELISA) with enhanced chemiluminescent detection for simultaneous detection of metolcarb and carbaryl in...
A direct competitive enzyme-linked immunosorbent assay (ELISA) with enhanced chemiluminescent detection for simultaneous detection of metolcarb and carbaryl in agricultural products is reported. The concentrations of coating antibodies and enzyme tracer, as well as the effects of pH and methanol concentrations, were investigated. Under optimum conditions, the IC(50) of metolcarb and carbaryl were 4 and 0.3 microg kg(-1), respectively. Detection of metolcarb and carbaryl in fruit juices and vegetables was accomplished using simple, rapid and efficient extraction methods. Recoveries (n = 3) of spiked samples ranged 75-108% for metolcarb and 74-98% for carbaryl. Validation of the enhanced chemiluminescent immunosorbent assay was conducted by comparison of results with HPLC. The correlation between the data obtained using ELISA with enhanced chemiluminescent detection and HPLC was good (n = 9). Therefore, the enhanced chemiluminescent ELISA was suitable for quantitative simultaneously determination of metolcarb and carbaryl residue in agricultural products.
Topics: Beverages; Brassica; Carbaryl; Citrus sinensis; Cucumis sativus; Enzyme-Linked Immunosorbent Assay; Fruit; Insecticides; Luminescent Measurements; Molecular Structure; Pesticide Residues; Phenylcarbamates; Reproducibility of Results; Sensitivity and Specificity
PubMed: 20155539
DOI: 10.1080/19440040903403016 -
Biosensors & Bioelectronics May 2016A novel approach to synthesize molecularly imprinted polymer (MIP) nanoparticles using a MIL-101 support (a type of metal-organic framework) is reported herein for the...
A novel approach to synthesize molecularly imprinted polymer (MIP) nanoparticles using a MIL-101 support (a type of metal-organic framework) is reported herein for the first time; the sample is referred as MIL@MIP. The nanoparticles were well distributed within the polymer film, and exhibit an octahedral shape, satisfied thermal stability, and a high specific surface area (SSA) of 1579.43 m(2)g(-1). The adsorption behavior of MIL@MIP toward metolcarb in aqueous solution was subsequently examined. The synthesized MIL@MIP displayed satisfactory high transfer mass rates and a high selective adsorption affinity for metolcarb. Based on these results, a quartz crystal microbalance (QCM) sensor based on MIL@MIP was subsequently constructed and examined for the sensitive detection of metolcarb. Under optimal conditions, the detection limit of the system assessed in pear juice was 0.0689 mg L(-1) within a linear concentration range of 0.1-0.9 mg L(-1). MIL@MIP-QCM system combines the advantages of MIL-101 and molecularly imprinted technology (MIT), thereby achieving high detection sensitivity and selectivity. The current findings suggest the potential of MIL@MIP for detecting trace level pesticides and veterinary drugs for food safety and environmental control.
Topics: Adsorption; Biosensing Techniques; Coordination Complexes; Limit of Detection; Metal-Organic Frameworks; Metals; Molecular Imprinting; Nanoparticles; Pesticides; Phenylcarbamates; Polymers; Quartz Crystal Microbalance Techniques
PubMed: 26735869
DOI: 10.1016/j.bios.2015.12.071 -
Analytica Chimica Acta Sep 2008Five different haptens of the N-methylcarbamate insecticide metolcarb were designed and synthesized. All of the haptens were conjugated with ovalbumin (OVA) for the...
Five different haptens of the N-methylcarbamate insecticide metolcarb were designed and synthesized. All of the haptens were conjugated with ovalbumin (OVA) for the coating antigen, and one hapten containing all of the structure of metolcarb was conjugated with bovine serum albumin (BSA) for the immunogen. Two polyclonal antisera were raised against the BSA conjugate, and ten antibody/coating conjugate combinations were selected for studies of assay sensitivity and specificity for metolcarb. A class-specific combination was found, with the I50 of the assay ranged from 0.64 to 20.98 microg mL(-1) for seven tested N-methylcarbamate insecticides except for pirimicarb. Considering titer, I50 and cross-reactivity of all combinations of antibody/coating conjugate, a competitive indirect enzyme-linked immunosorbent assay (ELISA) in a homologous system, whose limit of detection (LoD) reached 1.4 ng mL(-1), was presented. The results of competitive ELISAs indicated that coating hapten structure can significantly affect not only assay sensitivity but also its specificity.
Topics: Animals; Carbamates; Cattle; Enzyme-Linked Immunosorbent Assay; Haptens; Immune Sera; Insecticides; Reproducibility of Results; Sensitivity and Specificity
PubMed: 18721544
DOI: 10.1016/j.aca.2008.07.003 -
Analytical and Bioanalytical Chemistry Aug 2009The development of a direct competitive enzyme-linked immunosorbent assay based on polyclonal antibodies for N-methylcarbamate insecticide metolcarb is described. Two...
The development of a direct competitive enzyme-linked immunosorbent assay based on polyclonal antibodies for N-methylcarbamate insecticide metolcarb is described. Two new haptens for the metolcarb were designed and synthesized. Both haptens were conjugated with keyhole limpet hemocyanin to form the immunogens. Four rabbits were immunized with the immunogens for production of polyclonal antibodies against metolcarb. Antisera titers were tested on the homologous coating antigens using a noncompetitive indirect enzyme-linked immunosorbent assay. The high titer antisera were used to develop the direct competitive enzyme-linked immunosorbent assay for the detection of metolcarb. The antibody-antigen combination with the highest selectivity for metolcarb was further optimized and its tolerance to changes in chemical conditions (ionic strength, pH value, and organic solvent) was studied. Under optimum conditions, the sensitivity and the limit of detection were determined to be 22 microg L(-1) and 1.2 microg L(-1) respectively. Determination of metolcarb in fruit juices and vegetables was accomplished by simple, rapid, and efficient extraction methods. Recoveries of metolcarb from spiked samples ranged from 80.5% to 109.5%. Validation of the developed immunosorbent assay was conducted by comparison of results from high-performance liquid chromatography. The correlation between the data obtained using developed immunosorbent assay and high-performance liquid chromatography was high (R2 = 0.9884). Therefore, the developed immunosorbent assay in this study was suitable for the rapid quantitative determination of metolcarb in agricultural products.
Topics: Animals; Antibodies; Beverages; Enzyme-Linked Immunosorbent Assay; Food Contamination; Haptens; Immune Sera; Pesticide Residues; Phenylcarbamates; Sensitivity and Specificity; Time Factors; Vegetables
PubMed: 19575189
DOI: 10.1007/s00216-009-2911-9 -
Analytica Chimica Acta May 2010A direct competitive enzyme linked immunosorbent assay in multi-enzyme tracers format for the simultaneous analysis of carbaryl and metolcarb in agricultural products is...
A direct competitive enzyme linked immunosorbent assay in multi-enzyme tracers format for the simultaneous analysis of carbaryl and metolcarb in agricultural products is described in this study. The concentrations of coating antibodies and enzyme tracer were studied. Under the optimum conditions, the limits of detection of carbaryl and metolcarb were 0.15 microg L(-1) and 1.2 microg L(-1), respectively. Determination of carbaryl and metolcarb in fruit juices and vegetables was accomplished by simple, rapid and efficient extraction methods. Recoveries of spiked samples were great than 70%. Validation of the immunosorbent assay was conducted by comparison of results from high performance liquid chromatography (HPLC). The correlations between the data obtained using multi-enzyme tracers enzyme linked immunosorbent assay and high performance liquid chromatography were good. Results indicated that the new strategy for developing immunoassay for simultaneous quantitative determination of carbaryl and metolcarb residues was suitable in this study.
Topics: Agriculture; Animals; Antibodies; Beverages; Carbaryl; Enzyme-Linked Immunosorbent Assay; Enzymes; Feasibility Studies; Malus; Pesticide Residues; Phenylcarbamates; Reproducibility of Results; Time Factors; Vegetables
PubMed: 20433968
DOI: 10.1016/j.aca.2010.03.051 -
Biosensors & Bioelectronics Feb 2015In this work, we presented a three-dimensional (3D) molecularly imprinted electrochemical sensor (MIECS) with novel strategy for ultrasensitive and specific...
Prussian blue mediated amplification combined with signal enhancement of ordered mesoporous carbon for ultrasensitive and specific quantification of metolcarb by a three-dimensional molecularly imprinted electrochemical sensor.
In this work, we presented a three-dimensional (3D) molecularly imprinted electrochemical sensor (MIECS) with novel strategy for ultrasensitive and specific quantification of metolcarb based on prussian blue (PB) mediated amplification combined with signal enhancement of ordered mesoporous carbon. The molecularly imprinted polymers were synthesized by electrochemically induced redox polymerization of para aminobenzoic acid (p-ABA) in the presence of template metolcarb. Ordered mesoporous carbon material (CMK-3) was introduced to enhance the electrochemical response by improving the structure of the modified electrodes and facilitating charge transfer processes of PB which was used as an inherent electrochemical active probe. The modification process for the working electrodes of the MIECS was characterized by scanning electron microscope (SEM) and cyclic voltammetry (CV), and several important parameters controlling the performance of the MIECS were investigated and optimized in detail. The MIECS with 3D structure had the advantages of ease of preparation, high porous surface structure, speedy response, ultrasensitivity, selectivity, reliable stability, good reproducibility and repeatability. Under the optimal conditions, the MIECS offered an excellent current response for metolcarb in the linear response range of 5.0 × 10(-10)-1.0 × 10(-4) mol L(-1) and the limit of detection (LOD) was calculated to be 9.3 × 10 (-11)mol L(-1) (S/N = 3). The proposed MIECS has been successfully applied for the determination of metolcarb in real samples with satisfactory recoveries. Furthermore, the construction route of this ultrasensitive 3D MIECS may provide a guideline for the determination of non-electroactive analytes in environmental control and food safety.
Topics: Carbon; Conductometry; Electrodes; Equipment Design; Equipment Failure Analysis; Ferrocyanides; Molecular Imprinting; Pesticides; Phenylcarbamates; Porosity; Reproducibility of Results; Sensitivity and Specificity
PubMed: 25240126
DOI: 10.1016/j.bios.2014.09.009 -
Journal of Chromatographic Science Sep 2008A method for the determination of metolcarb and diethofencarb in apples and apple juice is developed using solid-phase microextraction (SPME) coupled with...
A method for the determination of metolcarb and diethofencarb in apples and apple juice is developed using solid-phase microextraction (SPME) coupled with high-performance liquid chromatography (HPLC). The experimental conditions of SPME, such as the kind of extraction fiber, extraction time, stirring rate, pH of the extracting solution, and desorption conditions are optimized. The SPME is performed on a 60 microm polydimethylsiloxane/divinylbenzene fiber for 40 min at room temperature with the solution being stirred at 1100 rpm. The extracted pesticides on the SPME fiber are desorbed in the mobile phase into SPME-HPLC interface for HPLC analysis. Separations are carried out on a Baseline C18 column (4.6 i.d. x 250 mm, 5.0 microm) with acetonitrile-water (55/45, v/v) as the mobile phase at a flow rate of 1.0 mL/min, and photodiode-array detection at 210 nm. For apple samples, the method is linear for both metolcarb and diethofencarb in the range of 0.05-1.0 mg/kg (r > 0.99), with a detection limit (S/N = 3 ) of 15 and 5 microg/kg, respectively. For apple juice, the method is linear for both metholcarb and diethofencarb over the range of 0.05-1.0 mg/L (r > 0.99) with the detection limit (S/N = 3 ) of 15 and 3 microg/L, respectively. Excellent recovery and reproducibility values are achieved. The proposed method is shown to be simple, sensitive, and organic solvent-free, and is suitable for the determination of the two pesticides in apples and apple juice.
Topics: Beverages; Calibration; Chromatography, High Pressure Liquid; Hydrogen-Ion Concentration; Malus; Osmolar Concentration; Phenylcarbamates; Reproducibility of Results; Sensitivity and Specificity; Temperature
PubMed: 18796236
DOI: 10.1093/chromsci/46.8.751 -
Electrophoresis May 2012A capillary electrophoresis immunoassay (CEIA) was developed for the determination of trace metolcarb (MTMC) in food. The method was based on the competitive reactions...
A capillary electrophoresis immunoassay (CEIA) was developed for the determination of trace metolcarb (MTMC) in food. The method was based on the competitive reactions between fluorescently labeled MTMC tracer and free MTMC with a limited amount of anti-MTMC antibody and the separation and determination by CE with LIF detector. A fluorescent reagent, FITC was labeled on MTMC to construct an immunofluorescent probe. CEIA experimental parameters such as the pH value and concentration of the running buffer and separation voltage as well as incubation time were systematically investigated. Under the optimized conditions, fluorescently labeled antigen and antibody bound could be well separated within 3 min using Na₂B₄O₇/NaH₂PO₄ buffer (20:10 mmol/L, pH 9.0) for background electrolyte, 20 kV for the separation voltage, and 20°C for the column temperature. The linear range of the method was 0.25-50.0 μg/L with LOD 0.07 μg/L. The RSD for relative migration time and relative fluorescence intensity ratio were 2.90% (intraday) and 4.73% (intraday), respectively. The proposed method has been applied to determine the residue of MTMC in food samples with the satisfactory recovery.
Topics: Animals; Antibodies; Cucumis sativus; Electrophoresis, Capillary; Female; Food Analysis; Hydrogen-Ion Concentration; Immunoassay; Limit of Detection; Oryza; Pesticide Residues; Phenylcarbamates; Rabbits; Reproducibility of Results; Spectrometry, Fluorescence
PubMed: 22648817
DOI: 10.1002/elps.201100704