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Dongxing Yuan - One of the best experts on this subject based on the ideXlab platform.

  • a new anionic exchange stir bar sorptive extraction coating based on Monolithic Material for the extraction of inorganic anion
    Journal of Chromatography A, 2010
    Co-Authors: Xiaojia Huang, Jianbing Lin, Dongxing Yuan
    Abstract:

    A novel anionic exchange stir bar sorptive extraction (SBSE) coating based on poly(2-(methacryloyloxy)ethyltrimethylammonium chloride-co-divinylbenzene) Monolithic Material for the extraction of inorganic anion was prepared. The effect of preparation conditions such as ratio of functional monomer to cross-linker, content of porogenic solvent on the extraction efficiencies were investigated in detailed. The Monolithic Material was characterized by elemental analysis, scanning electron microscopy and infrared spectroscopy. In order to investigate the extraction capacity of the new coating for inorganic anion, the new SBSE was combined with ionic chromatography with conductivity detection, Br-, NO3-, PO4(3-) and SO4(2-) were selected as detected solutes. Several extractive parameters, including pH value and ionic strength in sample matrix, desorption solvent, extraction and desorption time were optimized. The results showed that strongly ionic strength did not favor the extraction of anlaytes. Under the optimum experimental conditions, low detection limits (S/N=3) and quantification limits (S/N=10) of the proposed method for the target anions were achieved within the range of 0.92-2.62 and 3.03-9.25 microg/L, respectively. The method also showed good linearity, simplicity, practicality and low cost for the extraction inorganic anions. Finally, the proposed method was successfully used to detect the two different trademarks of commercial purified water with satisfactory recovery in the range of 70.0-92.6%. To the best of our knowledge, this is the first to use SBSE to enrich inorganic anions.

  • preparation of a mixed stir bar for sorptive extraction based on Monolithic Material for the extraction of quinolones from wastewater
    Journal of Chromatography A, 2010
    Co-Authors: Xiaojia Huang, Dongxing Yuan, Ningning Qiu, Qingmei Lin
    Abstract:

    In this study, a novel mixed mode Monolithic Material was prepared and acted as the SBSE coating. The Monolithic Material was prepared by in situ copolymerization of methacrylic acid-3-sulfopropyl ester potassium salt (MASE) and divinylbenzene (DB) in the presence of a porogen solvent containing cyclohexanol, 1-dodecanol, and water with azobisisobutyronitrile as initiator. The influences of the contents of the porogen solvent and monomer in the polymerization mixture on the extraction performance were investigated thoroughly. Several characteristic techniques, such as elemental analysis, scanning electron microscopy and infrared spectroscopy were used to characterize the Monolithic Material. To achieve optimum extraction performance for quinolones, several parameters, including pH value, desorption solvent, ionic strength in sample matrix, extraction and desorption time were investigated. The results show that under the optimized experimental conditions, the method has good sensitivity, linearity, simplicity and low cost. The extraction performance of present method to the target compounds was compared with commercial SBSE which using polydimethylsiloxane as coating and other SBSEs which based on Monolithic Materials. The comparative results indicate that present SBSE can extract the analytes more effectively than other SBSEs because both ion-exchange and hydrophobic interactions contribute to the extraction of quinolones.

  • simple and sensitive monitoring of sulfonamide veterinary residues in milk by stir bar sorptive extraction based on Monolithic Material and high performance liquid chromatography analysis
    Journal of Chromatography A, 2009
    Co-Authors: Xiaojia Huang, Ningning Qiu, Dongxing Yuan
    Abstract:

    National Nature Science Foundation of China [20805039]; Youth Talent Foundation of Fujian Province [2006F3117]; Innovation Foundation of Xiamen University [XDKJCX20063007]

  • sensitive determination of strongly polar aromatic amines in water samples by stir bar sorptive extraction based on poly vinylimidazole divinylbenzene Monolithic Material and liquid chromatographic analysis
    Journal of Chromatography A, 2009
    Co-Authors: Xiaojia Huang, Dongxing Yuan
    Abstract:

    A simple and sensitive method for the determination of polar aromatic amines (PAAs) was developed using stir bar sorptive extraction (SBSE) coupling to high-performance liquid chromatography. A hydrophilic poly(vinylimidazole-divinylbenzene) (VIDB) Monolithic Material was prepared and acted as SBSE coating. The influences of polymerization conditions for VIDB on the extraction efficiency were investigated using aniline and 2,4-dinitroaniline as detected solutes. To achieve optimum extraction performance for PAAs, several parameters including extraction and desorption time, desorption solvent, ionic strength and pH value of sample matrix were investigated. The results showed that under the optimized experimental conditions, the method showed good sensitivity and excellent recoveries, as well as advantages such as linearity, simplicity, low cost and high feasibility. The extraction performance of present method to the target compounds also compared with commercial SBSE which using polydimethylsiloxane as coating and other SBSE which based on Monolithic Materials. Finally, the proposed method was successfully applied to the determination of PAAs in lake and sea waters, and excellent recoveries of spiked target compounds in real samples were obtained.

  • determination of steroid sex hormones in wastewater by stir bar sorptive extraction based on poly vinylpyridine ethylene dimethacrylate Monolithic Material and liquid chromatographic analysis
    Journal of Chromatography A, 2009
    Co-Authors: Xiaojia Huang, Jianbin Lin, Dongxing Yuan
    Abstract:

    In this study, a simple and rapid method was developed for the determination of seven steroid hormones in wastewater. Sample preparation and analysis were performed by stir bar sorptive extraction (SBSE) based on poly(vinylpyridine-ethylene dimethacrylate) Monolithic Material (SBSEM) combined with high-performance liquid chromatography with diode array detection. To achieve the optimum extraction performance, several main parameters, including extraction and desorption time, pH value and contents of inorganic salt in the sample matrix, were investigated. Under the optimized experimental conditions, the method showed good linearity and repeatability, as well as advantages such as sensitivity, simplicity, low cost and high feasibility. The extraction performance of SBSEM to the target compounds also compared with commercial SBSE which used polydimethylsiloxane as coating. Finally, the proposed method was successfully applied to the determination of the target compounds in wastewater samples. The recoveries of spiked target compounds in real samples ranged from 48.2% to 110%.

Xiaojia Huang - One of the best experts on this subject based on the ideXlab platform.

  • controlled porosity Monolithic Material as permselective ion exchange membranes
    Analytica Chimica Acta, 2011
    Co-Authors: Xiaojia Huang, Purnendu K Dasgupta
    Abstract:

    Ion exchange membranes (IEMs) are used in a variety of analytical devices, including suppressors, eluent generators and other components used in ion chromatography. Such membranes are flexible and undergo substantial dimensional changes on hydration. Presently the push to miniaturization continues; a resurgent interest in open tubular ion chromatography requires microscale adaptation of these components. Incorporating IEMs in microscale devices is difficult. Although both macroporous and microporous ion exchange Materials have been made for use as chromatographic packing, ion exchange Material used as membranes are porous only on a molecular scale. Because such pores have vicinal ion exchange sites, ions of the same charge sign as those of the fixed sites are excluded from the IEMs. Monolithic polymers, including ion exchangers derived therefrom, are presently extensively used. When used in a separation column, such a Monolithic structure contains an extensively connected porous network. We show here that by controlling the amount of porogen added during the synthesis of Monolithic polymers derived from ethylene dimethacrylate - glycidyl methacrylate, which are converted to an anion exchanger by treatment with trimethylamine, it is possible to obtain rigid ion exchange polymers that behave like IEMs and allow only one charge type of ions to pass through, i.e., are permselective. We demonstrate successful open tubular cation chromatography suppressor performance.

  • a new anionic exchange stir bar sorptive extraction coating based on Monolithic Material for the extraction of inorganic anion
    Journal of Chromatography A, 2010
    Co-Authors: Xiaojia Huang, Jianbing Lin, Dongxing Yuan
    Abstract:

    A novel anionic exchange stir bar sorptive extraction (SBSE) coating based on poly(2-(methacryloyloxy)ethyltrimethylammonium chloride-co-divinylbenzene) Monolithic Material for the extraction of inorganic anion was prepared. The effect of preparation conditions such as ratio of functional monomer to cross-linker, content of porogenic solvent on the extraction efficiencies were investigated in detailed. The Monolithic Material was characterized by elemental analysis, scanning electron microscopy and infrared spectroscopy. In order to investigate the extraction capacity of the new coating for inorganic anion, the new SBSE was combined with ionic chromatography with conductivity detection, Br-, NO3-, PO4(3-) and SO4(2-) were selected as detected solutes. Several extractive parameters, including pH value and ionic strength in sample matrix, desorption solvent, extraction and desorption time were optimized. The results showed that strongly ionic strength did not favor the extraction of anlaytes. Under the optimum experimental conditions, low detection limits (S/N=3) and quantification limits (S/N=10) of the proposed method for the target anions were achieved within the range of 0.92-2.62 and 3.03-9.25 microg/L, respectively. The method also showed good linearity, simplicity, practicality and low cost for the extraction inorganic anions. Finally, the proposed method was successfully used to detect the two different trademarks of commercial purified water with satisfactory recovery in the range of 70.0-92.6%. To the best of our knowledge, this is the first to use SBSE to enrich inorganic anions.

  • preparation of a mixed stir bar for sorptive extraction based on Monolithic Material for the extraction of quinolones from wastewater
    Journal of Chromatography A, 2010
    Co-Authors: Xiaojia Huang, Dongxing Yuan, Ningning Qiu, Qingmei Lin
    Abstract:

    In this study, a novel mixed mode Monolithic Material was prepared and acted as the SBSE coating. The Monolithic Material was prepared by in situ copolymerization of methacrylic acid-3-sulfopropyl ester potassium salt (MASE) and divinylbenzene (DB) in the presence of a porogen solvent containing cyclohexanol, 1-dodecanol, and water with azobisisobutyronitrile as initiator. The influences of the contents of the porogen solvent and monomer in the polymerization mixture on the extraction performance were investigated thoroughly. Several characteristic techniques, such as elemental analysis, scanning electron microscopy and infrared spectroscopy were used to characterize the Monolithic Material. To achieve optimum extraction performance for quinolones, several parameters, including pH value, desorption solvent, ionic strength in sample matrix, extraction and desorption time were investigated. The results show that under the optimized experimental conditions, the method has good sensitivity, linearity, simplicity and low cost. The extraction performance of present method to the target compounds was compared with commercial SBSE which using polydimethylsiloxane as coating and other SBSEs which based on Monolithic Materials. The comparative results indicate that present SBSE can extract the analytes more effectively than other SBSEs because both ion-exchange and hydrophobic interactions contribute to the extraction of quinolones.

  • simple and sensitive monitoring of sulfonamide veterinary residues in milk by stir bar sorptive extraction based on Monolithic Material and high performance liquid chromatography analysis
    Journal of Chromatography A, 2009
    Co-Authors: Xiaojia Huang, Ningning Qiu, Dongxing Yuan
    Abstract:

    National Nature Science Foundation of China [20805039]; Youth Talent Foundation of Fujian Province [2006F3117]; Innovation Foundation of Xiamen University [XDKJCX20063007]

  • sensitive determination of strongly polar aromatic amines in water samples by stir bar sorptive extraction based on poly vinylimidazole divinylbenzene Monolithic Material and liquid chromatographic analysis
    Journal of Chromatography A, 2009
    Co-Authors: Xiaojia Huang, Dongxing Yuan
    Abstract:

    A simple and sensitive method for the determination of polar aromatic amines (PAAs) was developed using stir bar sorptive extraction (SBSE) coupling to high-performance liquid chromatography. A hydrophilic poly(vinylimidazole-divinylbenzene) (VIDB) Monolithic Material was prepared and acted as SBSE coating. The influences of polymerization conditions for VIDB on the extraction efficiency were investigated using aniline and 2,4-dinitroaniline as detected solutes. To achieve optimum extraction performance for PAAs, several parameters including extraction and desorption time, desorption solvent, ionic strength and pH value of sample matrix were investigated. The results showed that under the optimized experimental conditions, the method showed good sensitivity and excellent recoveries, as well as advantages such as linearity, simplicity, low cost and high feasibility. The extraction performance of present method to the target compounds also compared with commercial SBSE which using polydimethylsiloxane as coating and other SBSE which based on Monolithic Materials. Finally, the proposed method was successfully applied to the determination of PAAs in lake and sea waters, and excellent recoveries of spiked target compounds in real samples were obtained.

Ningning Qiu - One of the best experts on this subject based on the ideXlab platform.

Jean M J Frechet - One of the best experts on this subject based on the ideXlab platform.

  • Monolithic porous polymer for on chip solid phase extraction and preconcentration prepared by photoinitiated in situ polymerization within a microfluidic device
    Analytical Chemistry, 2001
    Co-Authors: Mark H Davey, Frantisek Svec, Jean M J Frechet
    Abstract:

    Monolithic porous polymers have been prepared by photoinitiated polymerization within the channels of a microfluidic device and used for on-chip solid-phase extraction and preconcentration. The preparation of the Monolithic Material with hydrophobic and ionizable surface chemistries is easily achieved by copolymerization of butyl methacrylate with ethylene dimethacrylate, or 2-hydroxyethyl methacrylate and [2-(methacryloyloxy)ethyl]trimethylammonium chloride with ethylene dimethacrylate, respectively. The porous properties, and consequently the flow resistance, of the Monolithic device are controlled by the use of a mixture of hexane and methanol as a porogenic mixture. This mixture was designed to meet the specific requirements for pore formation within macroporous monoliths useful in the microfluidic formats. The low flow resistance enables high flow rates of up to 10 μL/min, which corresponds to a linear flow velocity of 50 mm/s and far exceeds the flow velocities typical of the common analytical micro...

  • molded rigid polymer monoliths as separation media for capillary electrochromatography
    Analytical Chemistry, 1997
    Co-Authors: Eric C Peters, Miroslav Petro, Frantisek Svec, Jean M J Frechet
    Abstract:

    Rigid, Monolithic capillary columns for reversed-phase electrochromatography have been prepared within the confines of untreated fused-silica capillaries in a single step by a simple copolymerization of ethylene dimethacrylate, butyl methacrylate, and 2-acrylamido-2-methyl-1-propanesulfonic acid in the presence of a porogenic solvent. The composition of the specifically designed ternary porogenic solvent allows fine control of the porous properties of the Monolithic Material over a broad range. While the electroosmotic flow through these capillary columns increases with both increasing pore size of the monolith and content of charged functionalities, better chromatographic properties have been observed for monoliths with larger surface area and hydrophobicity. Using this technique, Monolithic capillary columns with an efficiency higher than 120 000 plates/m have been easily obtained.

Zilin Chen - One of the best experts on this subject based on the ideXlab platform.

  • determination of breath gas composition of lung cancer patients using gas chromatography mass spectrometry with Monolithic Material sorptive extraction
    Biomedical Chromatography, 2015
    Co-Authors: Peng Gao, Yuki Hashi, Jun Fan, Zilin Chen
    Abstract:

    A gas chromatographic–mass spectrometric method with Monolithic Material sorptive extraction (MMSE) pretreatment was developed to determine the breath gas composition in lung cancer patients. MonoTrap silica Monolithic and hybrid adsorbent was selected as the extraction medium during MMSE, given its strong capacity to extract volatile organic compounds (VOC) from exhaled gas. Under the appropriate conditions, high extraction efficiency was achieved. Using the selected ion-monitoring mode, the limit of detection (signal-to-noise ratio 3) for the benzene series was 0.012–2.172 ng L−1. The limit of quantitation (signal-to-noise ratio, 10) was 0.042–7.24 ng L−1. The linearity range of the method was 4–400 ng L−1. Average recovery of the benzene series at lower concentrations was 65–74% (20 ng L−1). The relative standard deviation of benzene series contents determined within the linear range of detection was <10% of the mean level determined. Our proposed method is simple, rapid and sensitive, and can be competently applied to determine the breath gas composition of lung cancer patients. Copyright © 2014 John Wiley & Sons, Ltd.

  • determination of chiral jasmonates in flowers by gc ms after Monolithic Material sorptive extraction
    Journal of Agricultural and Food Chemistry, 2013
    Co-Authors: Yuki Hashi, Zilin Chen
    Abstract:

    A GC/MS method with Monolithic Material sorptive extraction (MMSE) pretreatment was developed to determine contents of the enantiomers of jasmonic acid and methyl jasmonate in flowers. To optimize MMSE extraction, several MMSE parameters were investigated, including extraction temperature, extraction time, and extraction solvent. Under the optimal conditions, extraction efficiency was good. Using the selected-ion monitoring mode, the limit of detection (LOD, S/N = 3) for methyl jasmonates was 0.257 ng/mL. The limit of quantitation (LOQ, S/N = 10) was 0.856 ng/mL. The linearity range was 1–100 ng/mL. The average recovery of methyl jasmonate at lower concentration was 116.8% (2 ng/mL). The relative standard deviation of methyl jasmonate contents determined within the linear range of detection was less than or equal to 15% of the mean determined level. The proposed method is rapid, sensitive, and competently applied to the determination of jasmonic acid and methyl jasmonate enantiomers in flowers.