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Shuo Wang - One of the best experts on this subject based on the ideXlab platform.
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Sensitive and selective electrochemical determination of Quinoxaline-2-Carboxylic Acid based on bilayer of novel poly(pyrrole) functional composite using one-step electro-polymerization and molecularly imprinted poly(o-phenylenediamine).
Analytica Chimica Acta, 2014Co-Authors: Yukun Yang, Guozhen Fang, Xiaomin Wang, Mingfei Pan, Hailong Qian, Huilin Liu, Shuo WangAbstract:Abstract A facile and efficient molecularly imprinted polymer (MIP) recognition element of electrochemical sensor was fabricated by directly electro-polymerizing monomer o-phenylenediamine (oPD) in the presence of template Quinoxaline-2-Carboxylic Acid (QCA), based on one-step controllable electrochemical modification of poly(pyrrole)-graphene oxide-binuclear phthalocyanine cobalt (II) sulphonate (PPY-GO-BiCoPc) functional composite on glassy carbon electrode (GCE). The MIP film coated on PPY-GO-BiCoPc functional composite decorated GCE (MIP/PPY-GO-BiCoPc/GCE) was presented for the first time. The synergistic effect and electro-catalytic activity toward QCA redox of PPY-GO-BiCoPc functional composite were discussed using various contrast tests. Also, the effect of experimental variables on the current response such as, electro-polymerization cycles, template/monomer ratio, elution condition for template removal, pH of the supporting electrolyte and accumulation time, were investigated in detail. Under the optimized conditions, the proposed MIP sensor possessed a fast rebinding dynamics and an excellent recognition capacity to QCA, while the anodic current response of square wave voltammetry (SWV) was well-proportional to the concentration of QCA in the range of 1.0 × 10 −8 –1.0 × 10 −4 and 1.0 × 10 −4 –5.0 × 10 −4 mol L −1 with a low detection limit of 2.1 nmol L −1 . The established sensor was applied successfully to determine QCA in commercial pork and chicken muscle samples with acceptable recoveries (91.6–98.2%) and satisfactory precision (1.9–3.5% of SD), demonstrating a promising feature for applying the MIP sensor to the measurement of QCA in real samples.
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electrochemical sensor based on molecularly imprinted polymer film via sol gel technology and multi walled carbon nanotubes chitosan functional layer for sensitive determination of quinoxaline 2 carboxylic Acid
Biosensors and Bioelectronics, 2013Co-Authors: Yukun Yang, Guozhen Fang, Xiaomin Wang, Lingjie Kong, Xinlei He, Shuo WangAbstract:Abstract Quinoxaline-2-Carboxylic Acid (QCA) is difficult to measure since only trace levels are present in commercial meat products. In this study, a rapid, sensitive and selective molecularly imprinted electrochemical sensor for QCA determination was successfully constructed by combination of a novel modified glassy carbon electrode (GCE) and differential pulse voltammetry (DPV). The GCE was fabricated via stepwise modification of multi-walled carbon nanotubes (MWNTs)-chitosan (CS) functional composite and a sol–gel molecularly imprinted polymer (MIP) film on the surface. MWNTs-CS composite was used to enhance the electron transfer rate and expand electrode surface area, and consequently amplify QCA reduction electrochemical response. The imprinted mechanism and experimental parameters affecting the performance of MIP film were discussed in detail. The resulting MIP/sol–gel/MWNTs-CS/GCE was characterized using various electrochemical methods involving cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and DPV. The sensor using MIP/sol–gel/MWNTs-CS/GCE as working electrode showed a linear current response to the target QCA concentration in the wide range from 2.0×10 −6 to 1.0×10 −3 mol L −1 with a low detection limit of 4.4×10 −7 mol L −1 ( S / N =3). The established sensor with excellent reproductivity and stability was applied to evaluate commercial pork products. At five concentration levels, the recoveries and standard deviations were calculated as 93.5–98.6% and 1.7–3.3%, respectively, suggesting the proposed sensor is promising for the accurate quantification of QCA at trace levels in meat samples.
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A sensitive and selective imprinted solid phase extraction coupled to HPLC for simultaneous detection of trace Quinoxaline-2-Carboxylic Acid and methyl-3-Quinoxaline-2-Carboxylic Acid in animal muscles.
Food Chemistry, 2013Co-Authors: Zhenjuan Duan, Guozhen Fang, Lipeng Fan, Shuo WangAbstract:A new molecularly imprinted polymer (MIP), selective for major metabolites of quinoxaline-1,4-dioxides, was prepared through bulk polymerisation using Quinoxaline-2-Carboxylic Acid (QCA) as template, diethylaminoethylmethacrylate as functional monomer and ethylene glycol dimethacrylate as cross-linker in tetrahydrofuran. The synthesised MIP was characterised by Fourier transform infrared and adsorption experiments. MIP exhibited high affinity, fast kinetics for QCA and good selectivity for QCA and methyl-3-Quinoxaline-2-Carboxylic Acid (MQCA). MIP obtained was used as a selective sorbent for molecularly imprinted solid phase extraction (MISPE) coupled with HPLC to detect QCA and MQCA. Under the optimal conditions, the limits of detection (S/N=3) of porcine, chicken and fish muscles were 0.1, 0.3, 0.1 μg/kg for QCA and 0.2, 0.3, 0.1 μg/kg for MQCA, respectively and good recoveries were obtained in the range from 60.0 to 119.4%. These results indicated the MISPE-HPLC procedure could be successfully used for the determination QCA and MQCA in animal muscles.
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Electrochemical sensor based on molecularly imprinted polymer film via sol–gel technology and multi-walled carbon nanotubes-chitosan functional layer for sensitive determination of Quinoxaline-2-Carboxylic Acid
Biosensors and Bioelectronics, 2013Co-Authors: Yukun Yang, Guozhen Fang, Xiaomin Wang, Lingjie Kong, Guiyang Liu, Mingfei Pan, Shuo WangAbstract:Abstract Quinoxaline-2-Carboxylic Acid (QCA) is difficult to measure since only trace levels are present in commercial meat products. In this study, a rapid, sensitive and selective molecularly imprinted electrochemical sensor for QCA determination was successfully constructed by combination of a novel modified glassy carbon electrode (GCE) and differential pulse voltammetry (DPV). The GCE was fabricated via stepwise modification of multi-walled carbon nanotubes (MWNTs)-chitosan (CS) functional composite and a sol–gel molecularly imprinted polymer (MIP) film on the surface. MWNTs-CS composite was used to enhance the electron transfer rate and expand electrode surface area, and consequently amplify QCA reduction electrochemical response. The imprinted mechanism and experimental parameters affecting the performance of MIP film were discussed in detail. The resulting MIP/sol–gel/MWNTs-CS/GCE was characterized using various electrochemical methods involving cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and DPV. The sensor using MIP/sol–gel/MWNTs-CS/GCE as working electrode showed a linear current response to the target QCA concentration in the wide range from 2.0×10 −6 to 1.0×10 −3 mol L −1 with a low detection limit of 4.4×10 −7 mol L −1 ( S / N =3). The established sensor with excellent reproductivity and stability was applied to evaluate commercial pork products. At five concentration levels, the recoveries and standard deviations were calculated as 93.5–98.6% and 1.7–3.3%, respectively, suggesting the proposed sensor is promising for the accurate quantification of QCA at trace levels in meat samples.
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novel surface molecularly imprinted sol gel polymer applied to the online solid phase extraction of methyl 3 quinoxaline 2 carboxylic Acid and quinoxaline 2 carboxylic Acid from pork muscle
Analytical and Bioanalytical Chemistry, 2011Co-Authors: Zhenjuan Duan, Guozhen Fang, Lipeng Fan, Shuo WangAbstract:A new molecularly imprinted polymer (MIP), selective for major metabolites of quinoxaline-1,4-dioxides was firstly prepared by combining surface molecular imprinting technique with the sol–gel process. Methyl-3-Quinoxaline-2-Carboxylic Acid (MQCA) was used as template, 3-aminopropyltriethoxysilane as functional monomer, and tetraethoxysilicane as cross-linker. The MIP was characterized by Fourier transform infrared and evaluated through static adsorption experiments. The results indicated that MIP had high adsorption capacity, fast binding kinetics for MQCA, and the polymer showed a high degree of cross-reactivity for Quinoxaline-2-Carboxylic Acid (QCA). The MIP was then applied as a selective sorbent in an online solid phase extraction (SPE) coupled with high-performance liquid chromatography (HPLC). For a 50-mL sample solution, enrichment factors of 1,349 and 1,046 for QCA and MQCA, respectively, and limits of detection (S/N = 3) of 0.8 and 2 ng L−1 for QCA and MQCA, respectively, were obtained (corresponding to 0.02 and 0.04 ng g−1 in solid samples for final 100 mL of sample solutions of 5 g of pork). The sample preparation protocol was simplified and only included one step extraction with acetonitrile (MeCN) after the release of target analytes through Acidic hydrolysis without further sample cleanup. The new MIP-SPE-HPLC method was successfully applied to the quantification of trace QCA and MQCA in pork muscle with good recoveries ranging from 67% to 80% and RSD below 8%.
Guozhen Fang - One of the best experts on this subject based on the ideXlab platform.
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Sensitive and selective electrochemical determination of Quinoxaline-2-Carboxylic Acid based on bilayer of novel poly(pyrrole) functional composite using one-step electro-polymerization and molecularly imprinted poly(o-phenylenediamine).
Analytica Chimica Acta, 2014Co-Authors: Yukun Yang, Guozhen Fang, Xiaomin Wang, Mingfei Pan, Hailong Qian, Huilin Liu, Shuo WangAbstract:Abstract A facile and efficient molecularly imprinted polymer (MIP) recognition element of electrochemical sensor was fabricated by directly electro-polymerizing monomer o-phenylenediamine (oPD) in the presence of template Quinoxaline-2-Carboxylic Acid (QCA), based on one-step controllable electrochemical modification of poly(pyrrole)-graphene oxide-binuclear phthalocyanine cobalt (II) sulphonate (PPY-GO-BiCoPc) functional composite on glassy carbon electrode (GCE). The MIP film coated on PPY-GO-BiCoPc functional composite decorated GCE (MIP/PPY-GO-BiCoPc/GCE) was presented for the first time. The synergistic effect and electro-catalytic activity toward QCA redox of PPY-GO-BiCoPc functional composite were discussed using various contrast tests. Also, the effect of experimental variables on the current response such as, electro-polymerization cycles, template/monomer ratio, elution condition for template removal, pH of the supporting electrolyte and accumulation time, were investigated in detail. Under the optimized conditions, the proposed MIP sensor possessed a fast rebinding dynamics and an excellent recognition capacity to QCA, while the anodic current response of square wave voltammetry (SWV) was well-proportional to the concentration of QCA in the range of 1.0 × 10 −8 –1.0 × 10 −4 and 1.0 × 10 −4 –5.0 × 10 −4 mol L −1 with a low detection limit of 2.1 nmol L −1 . The established sensor was applied successfully to determine QCA in commercial pork and chicken muscle samples with acceptable recoveries (91.6–98.2%) and satisfactory precision (1.9–3.5% of SD), demonstrating a promising feature for applying the MIP sensor to the measurement of QCA in real samples.
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electrochemical sensor based on molecularly imprinted polymer film via sol gel technology and multi walled carbon nanotubes chitosan functional layer for sensitive determination of quinoxaline 2 carboxylic Acid
Biosensors and Bioelectronics, 2013Co-Authors: Yukun Yang, Guozhen Fang, Xiaomin Wang, Lingjie Kong, Xinlei He, Shuo WangAbstract:Abstract Quinoxaline-2-Carboxylic Acid (QCA) is difficult to measure since only trace levels are present in commercial meat products. In this study, a rapid, sensitive and selective molecularly imprinted electrochemical sensor for QCA determination was successfully constructed by combination of a novel modified glassy carbon electrode (GCE) and differential pulse voltammetry (DPV). The GCE was fabricated via stepwise modification of multi-walled carbon nanotubes (MWNTs)-chitosan (CS) functional composite and a sol–gel molecularly imprinted polymer (MIP) film on the surface. MWNTs-CS composite was used to enhance the electron transfer rate and expand electrode surface area, and consequently amplify QCA reduction electrochemical response. The imprinted mechanism and experimental parameters affecting the performance of MIP film were discussed in detail. The resulting MIP/sol–gel/MWNTs-CS/GCE was characterized using various electrochemical methods involving cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and DPV. The sensor using MIP/sol–gel/MWNTs-CS/GCE as working electrode showed a linear current response to the target QCA concentration in the wide range from 2.0×10 −6 to 1.0×10 −3 mol L −1 with a low detection limit of 4.4×10 −7 mol L −1 ( S / N =3). The established sensor with excellent reproductivity and stability was applied to evaluate commercial pork products. At five concentration levels, the recoveries and standard deviations were calculated as 93.5–98.6% and 1.7–3.3%, respectively, suggesting the proposed sensor is promising for the accurate quantification of QCA at trace levels in meat samples.
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A sensitive and selective imprinted solid phase extraction coupled to HPLC for simultaneous detection of trace Quinoxaline-2-Carboxylic Acid and methyl-3-Quinoxaline-2-Carboxylic Acid in animal muscles.
Food Chemistry, 2013Co-Authors: Zhenjuan Duan, Guozhen Fang, Lipeng Fan, Shuo WangAbstract:A new molecularly imprinted polymer (MIP), selective for major metabolites of quinoxaline-1,4-dioxides, was prepared through bulk polymerisation using Quinoxaline-2-Carboxylic Acid (QCA) as template, diethylaminoethylmethacrylate as functional monomer and ethylene glycol dimethacrylate as cross-linker in tetrahydrofuran. The synthesised MIP was characterised by Fourier transform infrared and adsorption experiments. MIP exhibited high affinity, fast kinetics for QCA and good selectivity for QCA and methyl-3-Quinoxaline-2-Carboxylic Acid (MQCA). MIP obtained was used as a selective sorbent for molecularly imprinted solid phase extraction (MISPE) coupled with HPLC to detect QCA and MQCA. Under the optimal conditions, the limits of detection (S/N=3) of porcine, chicken and fish muscles were 0.1, 0.3, 0.1 μg/kg for QCA and 0.2, 0.3, 0.1 μg/kg for MQCA, respectively and good recoveries were obtained in the range from 60.0 to 119.4%. These results indicated the MISPE-HPLC procedure could be successfully used for the determination QCA and MQCA in animal muscles.
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Electrochemical sensor based on molecularly imprinted polymer film via sol–gel technology and multi-walled carbon nanotubes-chitosan functional layer for sensitive determination of Quinoxaline-2-Carboxylic Acid
Biosensors and Bioelectronics, 2013Co-Authors: Yukun Yang, Guozhen Fang, Xiaomin Wang, Lingjie Kong, Guiyang Liu, Mingfei Pan, Shuo WangAbstract:Abstract Quinoxaline-2-Carboxylic Acid (QCA) is difficult to measure since only trace levels are present in commercial meat products. In this study, a rapid, sensitive and selective molecularly imprinted electrochemical sensor for QCA determination was successfully constructed by combination of a novel modified glassy carbon electrode (GCE) and differential pulse voltammetry (DPV). The GCE was fabricated via stepwise modification of multi-walled carbon nanotubes (MWNTs)-chitosan (CS) functional composite and a sol–gel molecularly imprinted polymer (MIP) film on the surface. MWNTs-CS composite was used to enhance the electron transfer rate and expand electrode surface area, and consequently amplify QCA reduction electrochemical response. The imprinted mechanism and experimental parameters affecting the performance of MIP film were discussed in detail. The resulting MIP/sol–gel/MWNTs-CS/GCE was characterized using various electrochemical methods involving cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and DPV. The sensor using MIP/sol–gel/MWNTs-CS/GCE as working electrode showed a linear current response to the target QCA concentration in the wide range from 2.0×10 −6 to 1.0×10 −3 mol L −1 with a low detection limit of 4.4×10 −7 mol L −1 ( S / N =3). The established sensor with excellent reproductivity and stability was applied to evaluate commercial pork products. At five concentration levels, the recoveries and standard deviations were calculated as 93.5–98.6% and 1.7–3.3%, respectively, suggesting the proposed sensor is promising for the accurate quantification of QCA at trace levels in meat samples.
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novel surface molecularly imprinted sol gel polymer applied to the online solid phase extraction of methyl 3 quinoxaline 2 carboxylic Acid and quinoxaline 2 carboxylic Acid from pork muscle
Analytical and Bioanalytical Chemistry, 2011Co-Authors: Zhenjuan Duan, Guozhen Fang, Lipeng Fan, Shuo WangAbstract:A new molecularly imprinted polymer (MIP), selective for major metabolites of quinoxaline-1,4-dioxides was firstly prepared by combining surface molecular imprinting technique with the sol–gel process. Methyl-3-Quinoxaline-2-Carboxylic Acid (MQCA) was used as template, 3-aminopropyltriethoxysilane as functional monomer, and tetraethoxysilicane as cross-linker. The MIP was characterized by Fourier transform infrared and evaluated through static adsorption experiments. The results indicated that MIP had high adsorption capacity, fast binding kinetics for MQCA, and the polymer showed a high degree of cross-reactivity for Quinoxaline-2-Carboxylic Acid (QCA). The MIP was then applied as a selective sorbent in an online solid phase extraction (SPE) coupled with high-performance liquid chromatography (HPLC). For a 50-mL sample solution, enrichment factors of 1,349 and 1,046 for QCA and MQCA, respectively, and limits of detection (S/N = 3) of 0.8 and 2 ng L−1 for QCA and MQCA, respectively, were obtained (corresponding to 0.02 and 0.04 ng g−1 in solid samples for final 100 mL of sample solutions of 5 g of pork). The sample preparation protocol was simplified and only included one step extraction with acetonitrile (MeCN) after the release of target analytes through Acidic hydrolysis without further sample cleanup. The new MIP-SPE-HPLC method was successfully applied to the quantification of trace QCA and MQCA in pork muscle with good recoveries ranging from 67% to 80% and RSD below 8%.
Zonghui Yuan - One of the best experts on this subject based on the ideXlab platform.
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A Convenient and Sensitive LC-MS/MS Method for Simultaneous Determination of Carbadox- and Olaquindox-Related Residues in Swine Muscle and Liver Tissues.
Journal of Analytical Methods in Chemistry, 2018Co-Authors: Heying Zhang, Lingli Huang, Dongmei Chen, Yuanhu Pan, Zhenli Liu, Yanfei Tao, Shuyu Xie, Zonghui YuanAbstract:This paper presents a convenient and sensitive LC-MS/MS method for the simultaneous determination of carbadox and olaquindox residues, including desoxyolaquindox (DOLQ), desoxycarbadox (DCBX), Quinoxaline-2-Carboxylic Acid (QCA), 3-methyl-Quinoxaline-2-Carboxylic Acid (MQCA), and the glycine conjugates of QCA and MQCA (namely, QCA-glycine and MQCA-glycine, resp.) in swine muscle and liver tissues. Tissue samples were extracted with 2% metaphosphoric Acid in 20% methanol and cleaned up by solid-phase extraction (SPE) on a mixed-mode anion-exchange column (Oasis MAX). Analysis was performed on a C18 column by detection with mass spectrometry in the multiple reaction monitoring (MRM) mode. The limits of detection (LODs) of the six analytes were determined to be 0.01 μg·kg−1 to 0.25 μg·kg−1, and the limits of quantification (LOQs) were 0.02 μg·kg−1 to 0.5 μg·kg−1. The total recoveries of the six analytes in all tissues were higher than 79.1% with the RSD% less than 9.2%. The developed method can determine the real residue level of QCA and MQCA, whether they are present in free form or as glycine conjugates in tissues, together with the carcinogenic desoxy metabolites DCBX and DOLQ with high recovery. Therefore, this method was suitable for routine analysis of residue control programmes and the residue depletion study of CBX and OLQ on swine.
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Dietary exposure assessment of cyadox based on tissue depletion of cyadox and its major metabolites in pigs, chickens, and carp.
Journal of Veterinary Pharmacology and Therapeutics, 2017Co-Authors: Lingli Huang, Yuanhu Pan, Y M Qiu, L L Sun, Yanxin Wang, Zonghui YuanAbstract:The tissue kinetics of cyadox, an antibacterial agent used in food animals, and its major metabolites in pigs, chickens, and carp were investigated followed by a complete dietary exposure assessment to evaluate the food safety of cyadox. Cyadox and its major metabolites, bisdeoxycyadox (Cy1), 4-desoxycyadox (Cy2), N-(quinoxaline-2-methyl)-cyanide acetyl hydrazine (Cy4), Quinoxaline-2-Carboxylic Acid (Cy6), and 2-hydromethyl-3-hydroxy-quinoxaline (Cy12), were simultaneously quantitated with a high-performance liquid chromatography-ultraviolet (HPLC-UV) method. Pigs, chickens, and carp were fed with 150 mg/kg cyadox in feed for consecutive 60, 40, and 30 days, respectively. The residue amount of cyadox and its major metabolites in liver, kidney, muscle, and fat (skin) tissues was determined. Cy2 was below the limit of quantitation even at the withdrawal time of 6 hr, cyadox, Cy4, Cy6, and Cy12 could be detected at 6-24 hr with low level less than 50 μg/kg. By contrast, Cy1 persisted for 3 days in the kidney of pigs and chickens, and in the liver of carp. Based on these residue depletion data and previous toxicology results, the global estimated chronic dietary exposure assessment of cyadox for general population was conducted, indicating a zero withdrawal time (WDT) may be appropriate for cyadox in food animals when used in feed for prolonged administration. These results provide analytical techniques and safety standards suitable for residue monitoring of cyadox in food animals.
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An immunoaffinity column for the selective purification of 3-methyl-Quinoxaline-2-Carboxylic Acid from swine tissues and its determination by high-performance liquid chromatography with ultraviolet detection and a colloidal gold-based immunochromatog
Food Chemistry, 2017Co-Authors: Dapeng Peng, Yulian Wang, Dongmei Chen, Xiya Zhang, Yuanhu Pan, Zhenli Liu, Feng Sheng, Zonghui YuanAbstract:Abstract An immunoaffinity column (IAC) for the selective purification of 3-methyl-Quinoxaline-2-Carboxylic Acid (MQCA) from porcine muscle and the liver as well as the methods for its determination by high-performance liquid chromatography with ultraviolet detection (HPLC-UV) and a colloidal gold-based immunochromatographic assay (GICA) were developed. This is the first study that describes a clean-up method that employs an IAC for the determination of MQCA. Using the HPLC-UV method, the limits of detection and limits of quantification for MQCA in different samples were 1.0–3.0 μg kg −1 and 4.0–10.0 μg kg −1 , respectively. The average recoveries of MQCA that was spiked into samples at concentrations of 4.0–100 μg kg −1 were 80.1–87.7%, with relative standard deviations of less than 8.5%. Using the GICA method, the limits of detection for MQCA in different samples were 10 μg kg −1 and 50 μg kg −1 . No false negatives or false positives were observed.
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A novel hapten and monoclonal-based enzyme-linked immunosorbent assay for 3-methyl-Quinoxaline-2-Carboxylic Acid in edible animal tissues
Analytical Methods, 2015Co-Authors: Xiya Zhang, Yulian Wang, Dongmei Chen, Dapeng Peng, Yuanhu Pan, Zhenli Liu, Zonghui YuanAbstract:To monitor the illegal use of olaquindox (OLA) in animals, a novel hapten and monoclonal antibody for 3-methyl-Quinoxaline-2-Carboxylic Acid (MQCA), the marker residue for OLA, had been produced. And then, the monoclonal-based indirect competitive enzyme linked immunosorbent assay (ic-ELISA) has been established with simple sample preparation and clean-up. The obtained antibody 5B10 that has isotype IgG1 showed an IC50 value of 17.7 μg L−1 for MQCA and did not exhibit measurable cross-reactivity with other antibiotics. The limits of detection ranged from 1.9 μg kg−1 to 4.3 μg kg−1. The recoveries were from 74.2% to 98.9% with a maximum coefficient of variation of 17.3%. A good correlation between ELISA and HPLC results of the incurred tissues demonstrated the reliability of the developed ic-ELISA. It would be a useful tool for the screening of the residues of MQCA in the edible tissues of animals.
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Development and validation of an indirect competitive enzyme-linked immunosorbent assay for monitoring Quinoxaline-2-Carboxylic Acid in the edible tissues of animals.
Food Additives & Contaminants: Part A, 2011Co-Authors: Dapeng Peng, Yulian Wang, Dongmei Chen, Zuxin Zhang, Yanfei Tao, Zonghui YuanAbstract:The feed drug additive carbadox is a suspected carcinogen and mutagen. To monitor effectively residues of carbadox in the edible tissues of food-producing animals, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) to detect Quinoxaline-2-Carboxylic Acid, the marker residue of carbadox, was developed. Several haptens were synthesised and conjugated to the carrier protein. Nine female New Zealand white rabbits were immunised with the immunising conjugates to produce polyclonal antibodies according to the designed schemes of immunisation. The highly specific antibody that was very sensitive to N-butylquinoxaline-2-carboxamide with an IC50 value of 7.75 µg l−1 was selected for the development of an ic-ELISA. The standard curves based on the N-butylquinoxaline-2-carboxamide matrix calibration ranged from 0.2 to 51.2 µg l−1. The decision limit and detection capability of the ic-ELISA were 0.60 and 0.83 µg kg−1 for liver and 0.68 and 0.79 µg kg−1 for muscle of swine, respectively. The recoveri...
Yukun Yang - One of the best experts on this subject based on the ideXlab platform.
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Sensitive and selective electrochemical determination of Quinoxaline-2-Carboxylic Acid based on bilayer of novel poly(pyrrole) functional composite using one-step electro-polymerization and molecularly imprinted poly(o-phenylenediamine).
Analytica Chimica Acta, 2014Co-Authors: Yukun Yang, Guozhen Fang, Xiaomin Wang, Mingfei Pan, Hailong Qian, Huilin Liu, Shuo WangAbstract:Abstract A facile and efficient molecularly imprinted polymer (MIP) recognition element of electrochemical sensor was fabricated by directly electro-polymerizing monomer o-phenylenediamine (oPD) in the presence of template Quinoxaline-2-Carboxylic Acid (QCA), based on one-step controllable electrochemical modification of poly(pyrrole)-graphene oxide-binuclear phthalocyanine cobalt (II) sulphonate (PPY-GO-BiCoPc) functional composite on glassy carbon electrode (GCE). The MIP film coated on PPY-GO-BiCoPc functional composite decorated GCE (MIP/PPY-GO-BiCoPc/GCE) was presented for the first time. The synergistic effect and electro-catalytic activity toward QCA redox of PPY-GO-BiCoPc functional composite were discussed using various contrast tests. Also, the effect of experimental variables on the current response such as, electro-polymerization cycles, template/monomer ratio, elution condition for template removal, pH of the supporting electrolyte and accumulation time, were investigated in detail. Under the optimized conditions, the proposed MIP sensor possessed a fast rebinding dynamics and an excellent recognition capacity to QCA, while the anodic current response of square wave voltammetry (SWV) was well-proportional to the concentration of QCA in the range of 1.0 × 10 −8 –1.0 × 10 −4 and 1.0 × 10 −4 –5.0 × 10 −4 mol L −1 with a low detection limit of 2.1 nmol L −1 . The established sensor was applied successfully to determine QCA in commercial pork and chicken muscle samples with acceptable recoveries (91.6–98.2%) and satisfactory precision (1.9–3.5% of SD), demonstrating a promising feature for applying the MIP sensor to the measurement of QCA in real samples.
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electrochemical sensor based on molecularly imprinted polymer film via sol gel technology and multi walled carbon nanotubes chitosan functional layer for sensitive determination of quinoxaline 2 carboxylic Acid
Biosensors and Bioelectronics, 2013Co-Authors: Yukun Yang, Guozhen Fang, Xiaomin Wang, Lingjie Kong, Xinlei He, Shuo WangAbstract:Abstract Quinoxaline-2-Carboxylic Acid (QCA) is difficult to measure since only trace levels are present in commercial meat products. In this study, a rapid, sensitive and selective molecularly imprinted electrochemical sensor for QCA determination was successfully constructed by combination of a novel modified glassy carbon electrode (GCE) and differential pulse voltammetry (DPV). The GCE was fabricated via stepwise modification of multi-walled carbon nanotubes (MWNTs)-chitosan (CS) functional composite and a sol–gel molecularly imprinted polymer (MIP) film on the surface. MWNTs-CS composite was used to enhance the electron transfer rate and expand electrode surface area, and consequently amplify QCA reduction electrochemical response. The imprinted mechanism and experimental parameters affecting the performance of MIP film were discussed in detail. The resulting MIP/sol–gel/MWNTs-CS/GCE was characterized using various electrochemical methods involving cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and DPV. The sensor using MIP/sol–gel/MWNTs-CS/GCE as working electrode showed a linear current response to the target QCA concentration in the wide range from 2.0×10 −6 to 1.0×10 −3 mol L −1 with a low detection limit of 4.4×10 −7 mol L −1 ( S / N =3). The established sensor with excellent reproductivity and stability was applied to evaluate commercial pork products. At five concentration levels, the recoveries and standard deviations were calculated as 93.5–98.6% and 1.7–3.3%, respectively, suggesting the proposed sensor is promising for the accurate quantification of QCA at trace levels in meat samples.
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Electrochemical sensor based on molecularly imprinted polymer film via sol–gel technology and multi-walled carbon nanotubes-chitosan functional layer for sensitive determination of Quinoxaline-2-Carboxylic Acid
Biosensors and Bioelectronics, 2013Co-Authors: Yukun Yang, Guozhen Fang, Xiaomin Wang, Lingjie Kong, Guiyang Liu, Mingfei Pan, Shuo WangAbstract:Abstract Quinoxaline-2-Carboxylic Acid (QCA) is difficult to measure since only trace levels are present in commercial meat products. In this study, a rapid, sensitive and selective molecularly imprinted electrochemical sensor for QCA determination was successfully constructed by combination of a novel modified glassy carbon electrode (GCE) and differential pulse voltammetry (DPV). The GCE was fabricated via stepwise modification of multi-walled carbon nanotubes (MWNTs)-chitosan (CS) functional composite and a sol–gel molecularly imprinted polymer (MIP) film on the surface. MWNTs-CS composite was used to enhance the electron transfer rate and expand electrode surface area, and consequently amplify QCA reduction electrochemical response. The imprinted mechanism and experimental parameters affecting the performance of MIP film were discussed in detail. The resulting MIP/sol–gel/MWNTs-CS/GCE was characterized using various electrochemical methods involving cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and DPV. The sensor using MIP/sol–gel/MWNTs-CS/GCE as working electrode showed a linear current response to the target QCA concentration in the wide range from 2.0×10 −6 to 1.0×10 −3 mol L −1 with a low detection limit of 4.4×10 −7 mol L −1 ( S / N =3). The established sensor with excellent reproductivity and stability was applied to evaluate commercial pork products. At five concentration levels, the recoveries and standard deviations were calculated as 93.5–98.6% and 1.7–3.3%, respectively, suggesting the proposed sensor is promising for the accurate quantification of QCA at trace levels in meat samples.
Zhenjuan Duan - One of the best experts on this subject based on the ideXlab platform.
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A sensitive and selective imprinted solid phase extraction coupled to HPLC for simultaneous detection of trace Quinoxaline-2-Carboxylic Acid and methyl-3-Quinoxaline-2-Carboxylic Acid in animal muscles.
Food Chemistry, 2013Co-Authors: Zhenjuan Duan, Guozhen Fang, Lipeng Fan, Shuo WangAbstract:A new molecularly imprinted polymer (MIP), selective for major metabolites of quinoxaline-1,4-dioxides, was prepared through bulk polymerisation using Quinoxaline-2-Carboxylic Acid (QCA) as template, diethylaminoethylmethacrylate as functional monomer and ethylene glycol dimethacrylate as cross-linker in tetrahydrofuran. The synthesised MIP was characterised by Fourier transform infrared and adsorption experiments. MIP exhibited high affinity, fast kinetics for QCA and good selectivity for QCA and methyl-3-Quinoxaline-2-Carboxylic Acid (MQCA). MIP obtained was used as a selective sorbent for molecularly imprinted solid phase extraction (MISPE) coupled with HPLC to detect QCA and MQCA. Under the optimal conditions, the limits of detection (S/N=3) of porcine, chicken and fish muscles were 0.1, 0.3, 0.1 μg/kg for QCA and 0.2, 0.3, 0.1 μg/kg for MQCA, respectively and good recoveries were obtained in the range from 60.0 to 119.4%. These results indicated the MISPE-HPLC procedure could be successfully used for the determination QCA and MQCA in animal muscles.
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novel surface molecularly imprinted sol gel polymer applied to the online solid phase extraction of methyl 3 quinoxaline 2 carboxylic Acid and quinoxaline 2 carboxylic Acid from pork muscle
Analytical and Bioanalytical Chemistry, 2011Co-Authors: Zhenjuan Duan, Guozhen Fang, Lipeng Fan, Shuo WangAbstract:A new molecularly imprinted polymer (MIP), selective for major metabolites of quinoxaline-1,4-dioxides was firstly prepared by combining surface molecular imprinting technique with the sol–gel process. Methyl-3-Quinoxaline-2-Carboxylic Acid (MQCA) was used as template, 3-aminopropyltriethoxysilane as functional monomer, and tetraethoxysilicane as cross-linker. The MIP was characterized by Fourier transform infrared and evaluated through static adsorption experiments. The results indicated that MIP had high adsorption capacity, fast binding kinetics for MQCA, and the polymer showed a high degree of cross-reactivity for Quinoxaline-2-Carboxylic Acid (QCA). The MIP was then applied as a selective sorbent in an online solid phase extraction (SPE) coupled with high-performance liquid chromatography (HPLC). For a 50-mL sample solution, enrichment factors of 1,349 and 1,046 for QCA and MQCA, respectively, and limits of detection (S/N = 3) of 0.8 and 2 ng L−1 for QCA and MQCA, respectively, were obtained (corresponding to 0.02 and 0.04 ng g−1 in solid samples for final 100 mL of sample solutions of 5 g of pork). The sample preparation protocol was simplified and only included one step extraction with acetonitrile (MeCN) after the release of target analytes through Acidic hydrolysis without further sample cleanup. The new MIP-SPE-HPLC method was successfully applied to the quantification of trace QCA and MQCA in pork muscle with good recoveries ranging from 67% to 80% and RSD below 8%.
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Simultaneous determination of five quinoxaline-1,4-dioxides and two major metabolites in surface water by on-line solid phase extraction coupled to high-performance liquid chromatography
Analytical Methods, 2011Co-Authors: Zhenjuan Duan, Guozhen Fang, Lipeng Fan, Mingfei Pan, Wei Liu, Shuo WangAbstract:Veterinary antibiotics are environmental contaminants of recent concern, so this study was designed to develop an analytical method of simultaneous determination for quinoxaline-1,4-dioxides (QdNOs) and their metabolites in the aqueous environment at trace levels. The new method is based on on-line solid phase extraction (SPE) using cigarette filter (CGFR) as the sorbent coupled to high-performance liquid chromatography (HPLC). Five QdNOs (carbadox, olaquindox, cyadox, mequindox, quinocetone) and two major metabolites (Quinoxaline-2-Carboxylic Acid and methyl-3-Quinoxaline-2-Carboxylic Acid) were detected in the surface water. The cleaned CGFR precolumn selectively retained target analytes when untreated water samples were upload by a flow-inject pump. Then the enriched extracts were subsequently eluted by HPLC mobile phase to the analytical column for chromatographic analysis. The on-line setup was uncomplicated and automated. The on-line SPE conditions were optimized in detail including sample pH, sample loading flow rate, sample volume, eluent, elution time and sorbents. Under the optimal experimental conditions, the enrichment factors were 33.3–630.0 by preconcentrating 25.0 mL of water samples. Limits of detection (S/N = 3) ranged from 1.6 to 24.3 ng L−1. Satisfactory recoveries were obtained and ranged from 87.1 to 107.5% at two spiked levels in real water samples with high precision (RSD, 1.3–3.8%). The on-line SPE-HPLC method is simple, rapid, reliable, sensitive and could be applied for multiresidue determination of the QdNOs and their metabolites in water samples.
