37 results on '"Hailin Cong"'
Search Results
2. Preparation and modification of PS-PMMA microspheres and their application in high performance liquid chromatography
- Author
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Yu Wang, Jingyuan Xiao, Hongtao Cao, Jie Xing, Hailin Cong, Youqing Shen, and Bing Yu
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Alkaloids ,Vancomycin ,General Chemical Engineering ,General Engineering ,Polystyrenes ,Polymethyl Methacrylate ,Methacrylates ,Benzene ,Methylmethacrylate ,Chromatography, High Pressure Liquid ,Microspheres ,Analytical Chemistry ,Anti-Bacterial Agents - Abstract
Polymer microspheres have been widely used as a stationary phase for liquid chromatography. In this work, we prepared and synthesized polystyrene-methyl methacrylate (PS-PMMA) microspheres, modified them, characterized the microspheres to have good chromatographic properties, and then used them as a high-performance liquid chromatography (HPLC) stationary phase to explore their applications. First, the PS-PMMA microspheres were hydrolyzed, and the separation of benzene homologues/alkaloids was explored. Then, on the basis of hydrolysis, diazo resin (DR) was used as a coupling agent to further modify the surface of the microspheres with amphoteric glycopeptide vancomycin. The modified microspheres were used as a HPLC stationary phase to explore the application of the stationary phase in the separation of chiral drugs. This work is important to broaden the application of functional chiral columns for antibiotics and to expand the application of PS-PMMA microspheres in HPLC.
- Published
- 2022
3. Recent development and application of membrane chromatography
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Jing Chen, Bing Yu, Hailin Cong, and Youqing Shen
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Chromatography ,Cricetulus ,Cricetinae ,Animals ,Antibodies, Monoclonal ,Membranes, Artificial ,CHO Cells ,Chromatography, Ion Exchange ,Biochemistry ,Chromatography, Affinity ,Analytical Chemistry - Abstract
Membrane chromatography is mainly used for the separation and purification of proteins and biological macromolecules in the downstream processing process, also applications in sewage disposal. Membrane chromatography is recognized as an effective alternative to column chromatography because it significantly improves chromatography from affinity, hydrophobicity, and ion exchange; the development status of membrane chromatography in membrane matrix and membrane equipment is thoroughly discussed, and the applications of protein capture and intermediate purification, virus, monoclonal antibody purification, water treatment, and others are summarized. This review will provide value for the exploration and potential application of membrane chromatography.
- Published
- 2022
4. Analysis of proteins and chiral drugs based on vancomycin covalent capillary electrophoretic coating
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Jie Xing, Fang Wang, Song Wang, Hailin Cong, Bing Yu, and Youqing Shen
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Chromatography ,biology ,Myoglobin ,Capillary action ,Electrophoresis, Capillary ,engineering.material ,Biochemistry ,Analytical Chemistry ,Electrophoresis ,chemistry.chemical_compound ,Adsorption ,Pharmaceutical Preparations ,chemistry ,Coating ,Vancomycin ,Covalent bond ,Electrochemistry ,biology.protein ,engineering ,Environmental Chemistry ,Muramidase ,Diazo ,Bovine serum albumin ,Spectroscopy - Abstract
Vancomycin is an amphoteric glycopeptide molecule, and its group diversity and chiral active sites provide a potential basis for its application in chromatographic analysis. In this article, using photosensitive diazo resin (DR) as the coupling agent, vancomycin is modified on the inner wall of the capillary to construct a capillary coating separation system. The highlight of the coated capillary is that it has both anti-protein adsorption and chiral separation properties. Compared with the bare capillary or non-covalently bonded DR/vancomycin-coated capillary, it can not only achieve the separation of four mixed proteins of lysozyme (Lys), bovine serum albumin (BSA), myoglobin (Mb), and ribonuclease A (RNase A), but also shows excellent performance in chiral drugs. The coated capillary effectively solves the problems of low efficiency of the separation column and high sample loss and provides ideas for the development of coated capillaries in the future.
- Published
- 2021
5. Preparation and application of urea-based derivatized β-cyclodextrin chiral stationary phase based on diazotized silica microspheres
- Author
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Xiangqiong He, Adeel Ahmed, Shuaibing Guo, Chuankui Kang, Youqing Shen, Hailin Cong, and Bing Yu
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Organic Chemistry ,beta-Cyclodextrins ,Urea ,Stereoisomerism ,General Medicine ,Silicon Dioxide ,Biochemistry ,Chromatography, High Pressure Liquid ,Microspheres ,Analytical Chemistry - Abstract
Recently, the design and development of efficient chiral stationary phases is still the core and goal of chiral chromatography. In order to quickly separate chiral drugs, we designed and prepared an environmentally friendly small particle chiral stationary phase: p-methylphenylurea-β-cyclodextrin chiral stationary phase (SiO
- Published
- 2021
6. Synthesis of 3,5-dichlorobenzene isocyanate-derived β-cyclodextrin and 3,5-dimethyl phenyl isocyanate-derived β-cyclodextrin chiral stationary phases and their applications in the separation of chiral compounds
- Author
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Shuai Lv, Chuanbao Ma, Hailin Cong, Youqing Shen, and Bing Yu
- Subjects
Filtration and Separation ,Analytical Chemistry - Published
- 2022
7. A review of the design of packing materials for ion chromatography
- Author
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Yu Wang, Hailin Cong, Youqing Shen, Xinyu Liu, and Bing Yu
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2019-20 coronavirus outbreak ,Chromatography ,Ion exchange ,Material analysis ,Chemistry ,010401 analytical chemistry ,Organic Chemistry ,Ion chromatography ,Materials Science ,Ionic bonding ,General Medicine ,010402 general chemistry ,Chromatography, Ion Exchange ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,Analytical Chemistry ,Ion ,Stationary phase ,Selectivity - Abstract
The development of ion chromatography has made remarkable progress in the past few decades, and it is now widely used for the analysis of common ions and organic compounds. Ion chromatography has many advantages, such as fast, high sensitivity, good selectivity and support for simultaneous analysis of multiple ionic compounds. In order to meet the high requirements of material analysis, new packing materials for ion chromatography with higher sensitivity and selectivity have been developed. In this paper, a lot of knowledge of ion chromatography is reviewed, and the development of ion chromatographic packings in recent years, especially in the last five years, is summarized.
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- 2021
8. Preparation of photosensitive diazotized poly (vinyl alcohol-b-styrene) covalent capillary coatings for capillary electrophoresis separation of proteins
- Author
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Qiaohong Peng, Bing Yu, Yifan Wang, Hailin Cong, Youqing Shen, Muhammad Usman, Adeel Ahmed, Yao Chen, and Xin Chen
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Vinyl alcohol ,Capillary action ,Ionic bonding ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Analytical Chemistry ,Styrene ,chemistry.chemical_compound ,Capillary electrophoresis ,Bovine serum albumin ,Chromatography ,biology ,010401 analytical chemistry ,Organic Chemistry ,Electrophoresis, Capillary ,Proteins ,General Medicine ,Photochemical Processes ,0104 chemical sciences ,chemistry ,Chemical engineering ,Covalent bond ,Polyvinyl Alcohol ,biology.protein ,Polystyrenes ,Protein adsorption - Abstract
In this paper, we have developed a novel method for the preparation of covalently connected capillary coatings in which diazotized poly (vinyl alcohol-b-styrene) (diazo-P(VA-b-St)) was used as a photosensitive coating agent. Firstly, the diazo-P(VA-b-St) coating was self-assembled on the inner surface of the capillary, and then irradiated by ultraviolet (UV) light to convert the ionic bonding into covalent bonding through the unique photochemical reaction of diazo groups. The covalently connected coatings inhibited the protein adsorption on the inner surface of the capillary, as a result, the baseline protein separation of ribonuclease A (RNase A), lysozyme (Lyz) and bovine serum albumin (BSA) were attained by utilizing the capillary electrophoresis (CE). The covalently connected diazo-P(VA-b-St) capillary coatings have greater CE separation performance with magnificent repeatability and enhanced stability, when compared with non-covalently coated or bare capillaries. This strategy to synthesize photosensitive diazo-P(VA-b-St) capillary coatings for their use in capillary electrophoresis separation of proteins is highly environment-friendly as it does not involve the use of extremely noxious and moisture penetrating coatings of silane.
- Published
- 2019
9. Heterogeneous activation of peroxymonosulfate using superparamagnetic β-CD-CoFe2O4 catalyst for the removal of endocrine-disrupting bisphenol A: Performance and degradation mechanism
- Author
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Bing Yu, Adeel Ahmed, Fengyuan Gao, Muhammad Usman, Youqing Shen, and Hailin Cong
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Bisphenol A ,chemistry.chemical_compound ,Reaction rate constant ,Quenching (fluorescence) ,chemistry ,Chemical engineering ,Radical ,Degradation (geology) ,Filtration and Separation ,Portable water purification ,Reaction intermediate ,Analytical Chemistry ,Catalysis - Abstract
The unintended leakage of endocrine-disrupting bisphenol A (BPA) from different industries into the aquatic environment has posed a severe threat to aquatic lives and human health. Herein, we explored a hydrothermal method to synthesize superparamagnetic β-cyclodextrin-cobalt ferrite (β-CD-CoFe2O4) catalyst for the selective capturing and efficient degradation of BPA through heterogeneous activation of peroxymonosulfate (PMS). The as-prepared catalysts were systematically characterized through multi-techniques to explore the relationship between their catalytic performance and material properties. Results showed that, in β-CD-CoFe2O4/PMS system, the degradation rate of BPA reached 99.23% in 60 min with a rate constant of 0.0708 min−1, approximately 16.09 times than CoFe2O4/PMS system (0.0044 min−1). Specifically, the large surface area and availability of more reactive sites of β-CD-CoFe2O4 boosted the activation process of PMS compared to pristine CoFe2O4, thus enhancing the degradation of BPA. Meanwhile, the effect of different operational parameters and co-existing anions on BPA degradation were also investigated. The generation of free radicals ( S O 4 ∙ - , ∙ O H , O 2 ∙ - , a n d 1 O 2 ) in the β-CD-CoFe2O4/PMS system liable for reducing BPA was corroborated through electron paramagnetic resonance analysis and quenching experiments. The possible degradation pathways of BPA were proposed based on the identification of reaction intermediates formed during the mineralization process. In brief, the findings of this study suggested that β-CD-CoFe2O4 is an efficient and environmentally friendly catalyst that facilitated the degradation of BPA through PMS activation. Moreover, the excellent magnetic separation, stability, and reusability of the β-CD-CoFe2O4 catalyst make them promising candidates for their water purification applications.
- Published
- 2021
10. Recent advances in detection technologies for COVID-19
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Hailin Cong, Bing Yu, Youqing Shen, and Tingting Han
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medicine.medical_specialty ,2019-20 coronavirus outbreak ,Respiratory illness ,Diagnostic methods ,Coronavirus disease 2019 (COVID-19) ,SARS-CoV-2 ,Chemistry ,Transmission (medicine) ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,COVID-19 ,Review ,Virus diseases ,Real-Time Polymerase Chain Reaction ,Detection technologies ,Analytical Chemistry ,COVID-19 Testing ,Pandemic ,medicine ,Humans ,Intensive care medicine ,Pandemics - Abstract
Corona Virus Disease 2019 (COVID-19) is a highly infectious respiratory illness that was caused by the SARS-CoV-2. It spread around the world in just a few months and became a worldwide pandemic. Quick and accurate diagnosis of infected patients is very important for controlling transmission. In addition to the commonly used Real-time reverse-transcription polymerase chain reaction (RT-PCR) detection techniques, other diagnostic techniques are also emerging endlessly. This article reviews the current diagnostic methods for COVID-19 and discusses their advantages and disadvantages. It provides an important reference for the diagnosis of COVID-19., Graphical abstract Image 1
- Published
- 2021
11. A covalent capillary coating of diazoresin and polyglycerol dendrimer for protein analysis using capillary electrophoresis
- Author
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Hailin Cong, Ming-Hong Wang, Guoling Li, and Bing Yu
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Glycerol ,Dendrimers ,Polymers ,Capillary action ,Clinical Biochemistry ,02 engineering and technology ,engineering.material ,01 natural sciences ,Biochemistry ,Analytical Chemistry ,Adsorption ,Capillary electrophoresis ,Coating ,Dendrimer ,Bovine serum albumin ,chemistry.chemical_classification ,Chromatography ,biology ,Protein Stability ,Chemistry ,010401 analytical chemistry ,Electrophoresis, Capillary ,Proteins ,Reproducibility of Results ,Polymer ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Covalent bond ,Linear Models ,engineering ,biology.protein ,0210 nano-technology ,Azo Compounds - Abstract
Overcoming proteins adsorption on the inner surface of capillary has attracted increasing attention recently. By using the unique photochemistry reaction of diazoresin (DR), a new covalent capillary coating was prepared on the fused-silica capillary through layer-by-layer self-assembly of DR with polyglycerol (PG) dendrimer. The separation performance of covalently DR/PG-dendrimer coated capillary noticeably exceeded the bare capillary and the noncovalently linked DR/PG-dendrimer capillary. A baseline separation of lysozyme, myoglobin, bovine serum albumin, and ribonuclease A was achieved using CE within 20 min. Besides, the covalently linked DR/PG-dendrimer coating has the remarkable stability and reproducibility. Especially, compared with the traditional method which use highly toxic and moisture-sensitive silane coupling agent, this method seems to be a simple and environmental friendly way to prepare the covalently coated capillaries for CE.
- Published
- 2017
12. A novel M2Ga2GeO7:N3+ (M = Ca, Ba, Sr; N = Cr, Nd, Er) sub-micron phosphor with multiband NIR emissions: preparation, structure, properties, and LEDs
- Author
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Youqing Shen, Yu Min, Zhihua Li, Bing Yu, Xin Ding, Bin He, and Hailin Cong
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Materials science ,Mechanical Engineering ,Doping ,Analytical chemistry ,Bioengineering ,Phosphor ,General Chemistry ,Crystal structure ,medicine.disease_cause ,law.invention ,Tetragonal crystal system ,Mechanics of Materials ,law ,medicine ,General Materials Science ,Electrical and Electronic Engineering ,Penetration depth ,Luminescence ,Ultraviolet ,Light-emitting diode - Abstract
Near-infrared (NIR) emission materials can be widely applied in various fields, such as food detection, imaging, treatment, electronic products. With the trend of miniaturization of equipment, smaller materials are needed. In this work, we successfully synthesized a series of M2Ga2GeO7: N3+ (M = Ca, Ba, Sr; N = Cr, Nd, Er) samples and then focused on the study of Nd3+ doped Sr2Ga2GeO7 (SGGO). A series of SGGO: xNd3+ sub-micron phosphors were prepared via a microwave-assisted sol-gel process combined with subsequent calcination at 750 ℃, and the structural information and luminescent properties were systematically studied. SGGO is a representative tetragonal crystal and belonging to the space group of P4(-)21m (113). The Nd3+ ions occupy eight-coordinated Sr2+ sites in the crystal lattice. From SEM analysis, the average particle size distribution is 219.7 ± 41.4 nm. The sub-micron phosphors have rich excitation spectra ranging from 350 nm to 850 nm and can produce multiband NIR emissions of 1331, 1056, and 905 nm when excited by ultraviolet and NIR light. The maximum emission intensity was obtained by optimizing the doping ratio of Nd3+ ions. A commercial chip was then utilized to fabricate light-emitting diodes (LEDs) to verify its application potential in NIR-II mini-LEDs. Compared with blue light LEDs, the as-prepared LEDs had good imaging penetration depth and could be clearly observed under 10 mm of chicken breast coverage. The maximum imaging penetration depth can be 33 mm.
- Published
- 2021
13. Yolk-shell Fe3O4@MOF-5 nanocomposites as a heterogeneous Fenton-like catalyst for organic dye removal
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Youqing Shen, Ruixia Yang, Bing Yu, Hailin Cong, and Qiaohong Peng
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Nanocomposite ,Materials science ,Filtration and Separation ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Analytical Chemistry ,Catalysis ,020401 chemical engineering ,Chemical engineering ,X-ray photoelectron spectroscopy ,Transmission electron microscopy ,Specific surface area ,0204 chemical engineering ,Fourier transform infrared spectroscopy ,0210 nano-technology ,Porosity ,Superparamagnetism - Abstract
Yolk-shell Fe3O4@MOF-5 nanocomposites were synthesized by utilizing a simple solvothermal method. The physicochemical properties of the yolk-shell Fe3O4@MOF-5 nanocomposites were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) and vibrating sample magnetometer (VSM) methods. The nanocomposites had a catalytic yolk, a hollow cavity and a porous shell. The nanocomposites had relatively high specific surface area of 203 m2 g−1 and showed superparamagnetic property. The catalytic activities of the yolk-shell Fe3O4@MOF-5 nanocomposites were evaluated by using methylene blue dye as a model pollutant. It is demonstrated that the yolk-shell Fe3O4@MOF-5 nanocomposites as a heterogeneous Fenton-like catalyst exhibited excellent catalysis since the internal cavity provided a relatively stable micro-environment for the reaction of the active ·OH radicals and the pollutants on the basis of the confinement effect. Furthermore, the yolk-shell Fe3O4@MOF-5 nanocomposites could be lightly separated from the pollutant solution by an external magnetic field and maintained good catalytic activity after five recycles, indicating the good stability of the nanocomposites.
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- 2021
14. Preparation of monodisperse porous polymeric ionic liquid microspheres and their application as stationary phases for HPLC
- Author
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Youqing Shen, Qiaohong Peng, Hailin Cong, Khalid Mahmood, Bing Yu, and Yue Wu
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Hydrophilic interaction chromatography ,010401 analytical chemistry ,Dispersity ,technology, industry, and agriculture ,Emulsion polymerization ,Ionic bonding ,02 engineering and technology ,Reversed-phase chromatography ,021001 nanoscience & nanotechnology ,01 natural sciences ,High-performance liquid chromatography ,0104 chemical sciences ,Analytical Chemistry ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Specific surface area ,Ionic liquid ,0210 nano-technology - Abstract
In recent decades, ionic liquid-modified packing materials as stationary phases of high performance liquid chromatography (HPLC) have attracted widespread attention due to their comprehensive properties. In this work, monodisperse porous polymeric ionic liquid microspheres were directly prepared using a seeded emulsion polymerization method and applied as stationary phase of HPLC. The effects of porogen, monomer and crosslinker on the properties of porous P(IL-DVB) microspheres were investigated in detail. Porous P(IL-DVB) microspheres with good stability, monodispersity and relatively high specific surface area were selected as stationary phase to successfully separate benzene and its homologues, and nucleosides and alkaloids under reversed phase chromatography (RPLC) mode and hydrophilic interaction chromatography (HILIC) mode, respectively.
- Published
- 2019
15. Novel antifouling polymer with self-cleaning efficiency as surface coating for protein analysis by electrophoresis
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Jie Xing, Fang Wang, Hailin Cong, Song Wang, Bing Yu, and Youqing Shen
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chemistry.chemical_classification ,Polymers ,Atom-transfer radical-polymerization ,Chemistry ,010401 analytical chemistry ,Proteins ,02 engineering and technology ,engineering.material ,Sulfonic acid ,021001 nanoscience & nanotechnology ,01 natural sciences ,Polymerization ,0104 chemical sciences ,Analytical Chemistry ,Surface coating ,Adsorption ,Chemical engineering ,Coating ,engineering ,Copolymer ,Surface modification ,0210 nano-technology ,Hydrophobic and Hydrophilic Interactions ,Protein adsorption - Abstract
The non-specific adsorption of protein has caused many problems in the application of materials. In this paper, a tri-block copolymer PEO-PNIPAAm-PSPMAP with double effects were obtained via atom transfer radical copolymerization (ATRP). The double-effect copolymer is covalently bonded to the hydrophobic material through a photosensitizer to achieve surface modification and applied to analytical chemistry. Sufficient hydratable groups (for instance, ether bonds, amide groups, and sulfonic acid groups) in the copolymer provides a basis for the anti-protein adsorption. At the same time, the interaction of the hydrophilic group and isopropyl group with temperature changes provides the possibility of elastic self-cleaning of the material, which is instrumental in extending the circulate lifetime of materials. Therefore, it is an environmentally friendly coating material. Besides, the effective antifouling performance and elastic self-cleaning function of the coating have been confirmed by the dynamic adsorption experiment of a fluorescent protein. The coating is used in capillary electrophoresis (CE), and its excellent protein separation spectrum verifies the practicality of the coating.
- Published
- 2021
16. Sugar fractionation using surface-modified nanofiltration membranes
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S. Ranil Wickramasinghe, Jianguo Tang, Mahdi Malmali, and Hailin Cong
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Chromatography ,Ultrafiltration ,Disaccharide ,Filtration and Separation ,02 engineering and technology ,Fractionation ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Polyelectrolyte ,0104 chemical sciences ,Analytical Chemistry ,chemistry.chemical_compound ,Membrane ,chemistry ,Chemical engineering ,Polysulfone ,Nanofiltration ,0210 nano-technology ,Selectivity - Abstract
Nanofiltration (NF) membranes were prepared using layer-by-layer (LbL) deposition of poly(sodium 4-styrenesulfonate) (PSS) and poly(diallyldimethylammonium chloride) (PDADMAC) on polysulfone (PSf) ultrafiltration (UF) membranes. The feasibility of using these NF membranes for fractionation of sugars was investigated. Deposition of polyelectrolyte multilayer (PEM) on the PSf membrane substrates was also confirmed by various characterization methods. Characterization results along with NF tests confirmed that pore-filling took place for 50 and 100 kDa PSf membranes. Results show that modified membranes were capable of separation/rejection of compounds with molecular weights in the range of mono- and disaccharide solutes. The 50 kDa base UF membrane modified with [PSS/PDADMAC] 7 PSS showed the best NF performance with sucrose to glucose selectivity of more than 11. In order to further enhance the separation factor and ensure a stable modification of the membrane, a novel method to convert the ionic bonded coatings into covalently bonded coatings has been developed.
- Published
- 2016
17. Self-assembled and covalently linked capillary coating of diazoresin and cyclodextrin-derived dendrimer for analysis of proteins by capillary electrophoresis
- Author
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Yuxing Han, Jianbin Tang, Qiaohong Peng, Hailin Cong, Ming Chi, and Bing Yu
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Dendrimers ,Ultraviolet Rays ,02 engineering and technology ,engineering.material ,01 natural sciences ,Analytical Chemistry ,Capillary electrophoresis ,Coating ,Dendrimer ,Polymer chemistry ,Animals ,Bovine serum albumin ,chemistry.chemical_classification ,Cyclodextrins ,Chromatography ,Cyclodextrin ,biology ,010401 analytical chemistry ,Layer by layer ,Electrophoresis, Capillary ,Proteins ,Photochemical Processes ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,chemistry ,Covalent bond ,biology.protein ,engineering ,Cattle ,0210 nano-technology ,Azo Compounds ,Protein adsorption - Abstract
Self-assembled and covalently linked capillary coatings of cyclodextrin-derived (CD) dendrimer were prepared using photosensitive diazoresin (DR) as a coupling agent. Layer by layer (LBL) self-assembled DR/CD-dendrimer coatings based on ionic bonding was fabricated first on the inner surface of capillary, and subsequently converted into covalent bonding after treatment with UV light through a unique photochemistry reaction of DR. Protein adsorption on the inner surface of capillary was suppressed by the DR/CD-dendrimer coating, and thus a baseline separation of lysozyme (Lys), myoglobin (Mb), bovine serum albumin (BSA) and ribonuclease A (RNase A) was achieved using capillary electrophoresis (CE). Compared with the bare capillary, the DR/CD-dendrimer covalently linked capillary coatings showed excellent protein separation performance with good stability and repeatability. Because of the replacement of highly toxic and moisture sensitive silane coupling agent by DR in the covalent coating preparation, this method may provide an environmentally friendly and simple way to prepare the covalently coated capillaries for CE.
- Published
- 2016
18. Detection of dopamine using carboxyl-La@C82 modified gold electrodes
- Author
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Ya-Nan Wu, Xiaoyan Zhang, Xiu-Lan Zhang, Qiaohong Peng, Hailin Cong, Bing Yu, and Hua Yuan
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Detection limit ,Materials science ,Analytical chemistry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Electrochemistry ,01 natural sciences ,Reference electrode ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Control and Systems Engineering ,Dopamine ,Electrode ,Materials Chemistry ,Ceramics and Composites ,medicine ,Electronic microscopy ,Differential pulse voltammetry ,Electrical and Electronic Engineering ,Cyclic voltammetry ,0210 nano-technology ,Nuclear chemistry ,medicine.drug - Abstract
Carboxyl-La@C82 modified the gold electrode was applied to the detection of dopamine (DA). The electrochemical behavior of the modified electrode was examined using the cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. Electrode surface morphology was characterized by scanning electronic microscopy (SEM). Compared with the bare electrode, the carboxyl-La@C82 modified electrode was more sensitive with a DA detection limit of 1.0 × 10−8 mol/L in the presence of uric acid (UA). In addition, the electrode was also applied to the detection of actual sample successfully. The good performance of the carboxyl-La@C82 modified electrode provided a promising alternative for DA analysis purpose and made great progresses in the detection for the dopamine by electrochemical sensors.
- Published
- 2016
19. Self-assembled covalent capillary coating of diazoresin/carboxyl fullerene for analysis of proteins by capillary electrophoresis and a comparison with diazoresin/graphene oxide coating
- Author
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Hua Yuan, Huwei Liu, Bing Yu, Xi Shu, Xin Chen, Hailin Cong, and Ming Chi
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Ionic bonding ,02 engineering and technology ,engineering.material ,01 natural sciences ,Biochemistry ,Chemistry Techniques, Analytical ,Analytical Chemistry ,law.invention ,Capillary electrophoresis ,Coating ,law ,Bovine serum albumin ,Chromatography ,biology ,Myoglobin ,Chemistry ,Graphene ,010401 analytical chemistry ,Organic Chemistry ,Layer by layer ,Cytochromes c ,Electrophoresis, Capillary ,Proteins ,Reproducibility of Results ,Serum Albumin, Bovine ,General Medicine ,Silicon Dioxide ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Covalent bond ,engineering ,biology.protein ,Graphite ,Muramidase ,Adsorption ,Fullerenes ,0210 nano-technology ,Azo Compounds ,Protein adsorption - Abstract
Self-assembled and covalently linked capillary coatings of carboxyl fullerenes (C60-COOH) were prepared using photosensitive diazoresin (DR) as a coupling agent. Layer by layer (LBL) self-assembled DR/C60-COOH coatings based on ionic bonding was fabricated first on the inner surface of silica capillary, and subsequently converted into covalent bonding after treatment with UV light through a unique photochemistry reaction of DR. The covalently bonded coatings had the ability of suppressing protein adsorption on the inner surface of silica capillary, and thus the baseline separation of lysozyme (Lys), cytochrome c (Cyt-c), bovine serum albumin (BSA) and myoglobin (Mb) was achieved within 13min by using capillary electrophoresis (CE). The covalently linked DR/C60-COOH capillary coatings presented good chemical stability and repeatability. The reproducibility of the separation of proteins was less than 1%, 2.5%, and 3.5%, respectively, for run-to-run, day-to-day, capillary-to-capillary, respectively; and the RSD of migration time for the proteins are all less than 2.5% after a continuous 100 times running in a coating column. Compared with DR/graphene oxide (GO) coatings prepared by the same method, the DR/C60-COOH capillary coatings showed excellent protein separation performance due to a self-lubrication based anti-fouling mechanism. Because of the replacement of highly toxic and moisture sensitive silane coupling agent by DR in the covalent coating preparation, this method may provide an environmentally friendly and simple way to prepare the covalently coated capillaries for CE.
- Published
- 2016
20. Synthesis of monodisperse poly(styrene-co-divinylbenzene) microspheres with binary porous structures and application in high-performance liquid chromatography
- Author
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Tao Xu, Chao Tian, Hailin Cong, and Bing Yu
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Dispersion polymerization ,Materials science ,Mechanical Engineering ,Dispersity ,Analytical chemistry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Divinylbenzene ,01 natural sciences ,High-performance liquid chromatography ,0104 chemical sciences ,Styrene ,chemistry.chemical_compound ,chemistry ,Polymerization ,Mechanics of Materials ,General Materials Science ,0210 nano-technology ,Porosity ,Benzene - Abstract
Monodisperse poly(styrene-co-divinylbenzene) (PS-DVB) microspheres with binary porous structures were synthesized using a modified seeded polymerization method. The microspheres had small pores on the surface and big pores in the middle. Using the binary porous PS-DVB (BPPSD) microspheres as packing materials for high-performance liquid chromatography, several benzene analogs were effectively separated in a column as short as 75 mm due to the high surface areas of the stationary phase. Because of the π–π affinity interaction between BPPSD particles and analytes, the separation performance of the BPPSD column was better than commercialized C18 column at the same conditions. Compared to column filled with non-porous PS-DVB particles, the back pressure of BPPSD column could be maintained at especially low level even at high flow rates due to the excellent permeability of the fillers. In addition, approximate baseline separation of C60 and C70 was also achieved in the 75 mm BPPSD column.
- Published
- 2016
21. Photosensitive polystyrene/silver bromide hybrid colloidal crystals as recoverable colorimetric naked eye probes for bromine gas sensing
- Author
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Bing Yu, Feng Zhai, Di Yang, and Hailin Cong
- Subjects
Materials science ,Bromine ,Analytical chemistry ,Bragg's law ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,General Chemistry ,Colloidal crystal ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Silver bromide ,01 natural sciences ,Silver nanoparticle ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Naked eye ,Polystyrene ,Absorption (chemistry) ,0210 nano-technology - Abstract
Photosensitive polystyrene (PS)/silver bromide (AgBr) hybrid colloidal crystals were prepared using a co-deposition method. After treatment with UV light, the infiltrated AgBr decomposed to silver nanoparticles (Ag-NPs), and PS/Ag-NP hybrid colloidal crystals with enhanced structural colours were obtained. The enhanced structural colors are due to the absorption of incoherent scattering light and increase in color saturation by the embedded Ag-NPs. The band gaps of the PS colloidal crystals, and PS/AgBr and PS/Ag-NP hybrid colloidal crystals were measured using a UV-vis reflection spectrometer and calculated using Bragg law. The obtained PS/Ag-NP hybrid colloidal crystals could be used as recoverable colorimetric naked eye probes for bromine (Br) gas sensing with a detection limit of 15 mmol L−1 at a sensing time of 50 s. The sensor had a very reliable performance after repeated bromine sensing, and could be mass produced facilely with very low cost.
- Published
- 2016
22. Synthesis and modification of monodisperse silica microspheres for UPLC separation of C60 and C70
- Author
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Qiaohong Peng, Lei Xue, Bing Yu, Chao Tian, Shu-Jing Yang, Xiaodan Xu, and Hailin Cong
- Subjects
Chromatography ,Materials science ,Fullerene ,General Chemical Engineering ,Dispersity ,General Engineering ,02 engineering and technology ,Electrolyte ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,High-performance liquid chromatography ,0104 chemical sciences ,Analytical Chemistry ,Tetraethyl orthosilicate ,chemistry.chemical_compound ,Ammonia ,chemistry ,Trichlorosilane ,Surface modification ,0210 nano-technology - Abstract
Monodisperse silica microspheres with average diameters from 1 μm to 2 μm were synthesized by a modified Stober method, in which an ethanolic solution of tetraethyl orthosilicate (TEOS) was continuously supplied to the reaction mixture containing KCl electrolyte, water, ethanol and ammonia. The effects of reactant amounts, supply rate, and reaction temperature on the microsphere morphology were investigated. After surface modification with octadecyl trichlorosilane, the obtained monodisperse C18-silica microspheres with an average diameter of 1.5 μm were applied to ultra performance liquid chromatography (UPLC) separation of fullerenes. Because of having a smaller size, the 1.5 μm monodisperse C18-silica UPLC stationary phase shows ultra high efficiency compared with the commercial C18-silica HPLC stationary phase with average diameters from 5 to 50 μm.
- Published
- 2016
23. Preparation of porous sulfonated poly(styrene-divinylbenzene) microspheres and its application in hydrophilic and chiral separation
- Author
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Jie Xing, Shuai Zhang, Youqing Shen, Hailin Cong, Xin Ding, and Bing Yu
- Subjects
Formic acid ,010401 analytical chemistry ,Dispersity ,Oxalic acid ,02 engineering and technology ,Porosimetry ,021001 nanoscience & nanotechnology ,Divinylbenzene ,01 natural sciences ,0104 chemical sciences ,Analytical Chemistry ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Specific surface area ,Particle size ,0210 nano-technology ,Acrylic acid - Abstract
Monodisperse cross-linked poly (styrene-divinylbenzene) (P(S-DVB)) porous microspheres with a particle size of about 10 μm were obtained by using the improved two-step seed swelling polymerization method. The influence of different crosslinking degree on specific surface area of porous microparticles was carefully investigated. The surface morphology and pore structure of seed microspheres and porous microspheres were characterized by scanning electron microscopy (SEM), accelerated surface area and porosimetry analyzer. Porous P(S-DVB) microparticles were sulfonated and used as a hydrophilic column packing material for high performance liquid chromatography (HPLC). The separation of oxalic acid, formic acid, acetic acid and acrylic acid was achieved by using the sulfonated-P(S-DVB) particles as packing materials in HPLC. The back pressure of sulfonated-P(S-DVB) column could be maintained at especially low level even at high flow rates due to the excellent permeability of the fillers. Moreover, the separation of chiral drugs was successfully carried out by using the chitosan coated sulfonated-P(S-DVB) microspheres as a column packing material in HPLC. By using water soluble non-toxic photosensitive diazoresin (DR) as linker, a green and facile way to modify packing materials was developed.
- Published
- 2020
24. Using ZIF-8 as stationary phase for capillary electrophoresis separation of proteins
- Author
-
Hailin Cong, Bing Yu, Zhong-Min Geng, and Qianqian Song
- Subjects
Capillary action ,Phenylalanine ,02 engineering and technology ,01 natural sciences ,Analytical Chemistry ,Capillary electrophoresis ,Capillary column ,Egg White Proteins ,Animals ,Metal-Organic Frameworks ,Electrostatic interaction ,Chromatography ,Chemistry ,Ligand ,010401 analytical chemistry ,Imidazoles ,Cytochromes c ,Electrophoresis, Capillary ,Proteins ,Reproducibility of Results ,Green Chemistry Technology ,Serum Albumin, Bovine ,Stereoisomerism ,Ribonuclease, Pancreatic ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Nanocrystal ,Stationary phase ,Zeolites ,Nanoparticles ,Cattle ,Muramidase ,0210 nano-technology ,Chickens - Abstract
Recently, the separation of proteins has received much attention, although many techniques require expensive instrumentation and trained analysts. In this work, a low-cost, effective, and environmental friendship capillary electrophoresis (CE) for proteins separation was first time introduced. The ZIF-8 with outstanding properties of large surface area, and accessible tunnels and cages were coated the inner surface of silica capillary as a separation media by electrostatic interaction. The fast baseline separation of Lys, CC, BSA and RNase A can be obtained within 10 min using the ZIF-8 nanocrystals coated capillary column under the optimum separation conditions. Meanwhile, this system showed good reproducibility and stability. Using L -glutamic acid as the selector ligand, the D - and L -phenylalanine were successfully separated by the ZIF-8 nanocrystals coated capillary column. Furthermore, the method was also applied to separate egg white proteins, and three main proteins were separated in a single run.
- Published
- 2018
25. Light-assisted preparation of vancomycin chiral stationary phase based on diazotized silica and its enantioseparation evaluation by high-performance liquid chromatography
- Author
-
Bing Yu, Hailin Cong, Shuai Zhang, and Guoling Li
- Subjects
Analyte ,Ultraviolet Rays ,Dispersity ,Ionic bonding ,02 engineering and technology ,01 natural sciences ,High-performance liquid chromatography ,Analytical Chemistry ,chemistry.chemical_compound ,Vancomycin ,Chromatography, High Pressure Liquid ,Chemistry ,Elution ,010401 analytical chemistry ,Green Chemistry Technology ,Stereoisomerism ,021001 nanoscience & nanotechnology ,Photochemical Processes ,Silicon Dioxide ,Silane ,Microspheres ,0104 chemical sciences ,Solutions ,Chemical engineering ,Covalent bond ,Enantiomer ,0210 nano-technology ,Azo Compounds - Abstract
Owing to enantiomers' identical physical and chemical properties, separation work in the chiral environments is still a great challenge.and chemical properties. Chromatographic techniques employing chiral stationary phases (CSPs) have been developed as powerful tools for the chiral analysis and preparation of pure enantiomers. Here we report a facile synthesis of vancomycin stationary phase based on diazotized silica. Monodisperse silica particles were synthesized by a modified Stober method. The obtained silica particles were modified by self-assembly photosensitive diazoresin (DR) and vancomycin on the surface. After treatment with UV light, the ionic bonding was converted into covalent bonding through a unique photochemistry reaction of DR. Baseline separation of chiral drugs was achieved by using the vancomycin@SiO2 particles as packing materials in high performance liquid chromatography (HPLC). The effects of separation parameters including elution mode, flow rate and analyte mass on the enantioselectivity of the CSP were investigated in detail. Due to the replacement of highly toxic and moisture sensitive silane agent by water soluble non-toxic DR in the modification of silica microspheres, this method provides a green and easy way to manufacture packing materials for chromatography applications.
- Published
- 2017
26. Inverse colloidal crystal membranes for hydrophobic interaction membrane chromatography
- Author
-
Xinying Wang, Hailin Cong, Bing Yu, Hua Yuan, Anh Vu, Jianguo Tang, S. Ranil Wickramasinghe, and Yongli Luo
- Subjects
Chromatography ,medicine.drug_class ,Synthetic membrane ,Filtration and Separation ,Colloidal crystal ,Monoclonal antibody ,Polyvinylidene fluoride ,Analytical Chemistry ,Hydrophobic effect ,chemistry.chemical_compound ,Membrane ,chemistry ,Protein purification ,medicine ,Porosity - Abstract
Hydrophobic interaction membrane chromatography has gained interest due to its excellent performance in the purification of humanized monoclonal antibodies. The membrane material used in hydrophobic interaction membrane chromatography has typically been commercially available polyvinylidene fluoride. In this contribution, newly developed inverse colloidal crystal membranes that have uniform pores, high porosity and, therefore, high surface area for protein binding are used as hydrophobic interaction membrane chromatography membranes for humanized monoclonal antibody immunoglobulin G purification. The capacity of the inverse colloidal crystal membranes developed here is up to ten times greater than commercially available polyvinylidene fluoride membranes with a similar pore size. This work highlights the importance of developing uniform pore size high porosity membranes in order to maximize the capacity of hydrophobic interaction membrane chromatography.
- Published
- 2015
27. Synthesis of monodisperse silica microspheres and modification with diazoresin for mixed-mode ultra high performance liquid chromatography separations
- Author
-
Hua Yuan, Chao Tian, Hailin Cong, Bing Yu, and Shuai Zhang
- Subjects
Materials science ,Chromatography ,Fullerene ,010401 analytical chemistry ,Dispersity ,Ionic bonding ,Filtration and Separation ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Analytical Chemistry ,Tetraethyl orthosilicate ,chemistry.chemical_compound ,chemistry ,Covalent bond ,Phase (matter) ,Ultraviolet light ,0210 nano-technology ,Benzene - Abstract
Monodisperse silica particles with average diameters of 1.9-2.9 μm were synthesized by a modified Stober method, in which tetraethyl orthosilicate was continuously supplied to the reaction mixture containing KCl electrolyte, water, ethanol, and ammonia. The obtained silica particles were modified by self-assembly with positively charged photosensitive diazoresin on the surface. After treatment with ultraviolet light, the ionic bonding between silica and diazoresin was converted into covalent bonding through a unique photochemistry reaction of diazoresin. Depending on the chemical structure of diazoresin and mobile phase composition, the diazoresin-modified silica stationary phase showed different separation mechanisms, including reversed phase and hydrophilic interactions. Therefore, a variety of baseline separation of benzene analogues and organic acids was achieved by using the diazoresin-modified silica particles as packing materials in ultra high performance liquid chromatography. According to the π-π interactional difference between carbon rings of fullerenes and benzene rings of diazoresin, C60 and C70 were also well separated by ultra-high performance liquid chromatography. Because it has a small size, the ∼2.5 μm monodisperse diazoresin-modified silica stationary phase shows ultra-high efficiency compared with the commercial C18 -silica high-performance liquid chromatography stationary phase with average diameters of ∼5 μm.
- Published
- 2017
28. Determination of Dopamine Using Self-Assembled Diazoresin/Graphene Modified Electrodes
- Author
-
Yi-Ying Yang, Bing Yu, Li-Xin Zhang, Jun Lu, Jin-Dou Zhang, Hua Yuan, Tian-Zi Hao, and Hailin Cong
- Subjects
Detection limit ,Reproducibility ,Materials science ,Graphene ,Analytical chemistry ,Condensed Matter Physics ,Electrochemistry ,Electronic, Optical and Magnetic Materials ,law.invention ,Control and Systems Engineering ,law ,Electrode ,Materials Chemistry ,Ceramics and Composites ,Differential pulse voltammetry ,Self-assembly ,Electrical and Electronic Engineering ,Cyclic voltammetry ,Nuclear chemistry - Abstract
Self-assembled ultrathin films of diazoresin (DR)/graphene (GR) were formed on thioglycollic acid (TGA) decorated gold (Au) electrodes by photo-crosslinking. The electrochemical behavior of dopamine (DA) at the DR/GR modified electrodes was studied using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. Under the optimal conditions, a sensitive DPV response to DA concentration was observed with the detection limit of 2.8 × 10−9 M. Moreover, the modified electrodes exhibited good reproducibility and sensitivity, demonstrating its feasibility for the analytical purpose.
- Published
- 2014
29. A novel diazoresin/poly(N -vinyl aminobutyric acid) covalent capillary coating for the analysis of proteins by capillary electrophoresis
- Author
-
Bing Yu, Hailin Cong, Mingming Jiao, Shu-Jing Yang, and Xi Shu
- Subjects
Polyvinylpyrrolidone ,Chemistry ,Capillary action ,Ionic bonding ,Filtration and Separation ,engineering.material ,Analytical Chemistry ,Hydrolysis ,Capillary electrophoresis ,Coating ,Covalent bond ,Polymer chemistry ,engineering ,medicine ,Organic chemistry ,Protein adsorption ,medicine.drug - Abstract
A novel method for the preparation of covalently linked capillary coatings of poly(N-vinyl aminobutyric acid) (PVAA) obtained from hydrolyzed polyvinylpyrrolidone was demonstrated using photosensitive diazoresin (DR) as a coupling agent. A layer-by-layer self-assembled film of DR and PVAA based on ionic bonding was first fabricated on the inner wall of capillary, then ionic bonding was converted into covalent bonding after treatment with UV light through a unique photochemical reaction of DR. The covalently bonded coatings suppressed protein adsorption on the inner surface of the capillary, and thus a baseline separation of lysozyme, cytochrome c, BSA, amyloglucosidase, and myoglobin was achieved using CE. Compared with bare capillary or noncovalently bonded DR/PVAA coatings, the covalently linked DR/PVAA capillary coatings not only improved the CE separation performance for proteins, but also exhibited good stability and repeatability. Due to the replacement of the highly toxic and moisture-sensitive silane coupling agent by DR in the covalent coating preparation, this method may provide a green and easy way to make covalently coated capillaries for CE.
- Published
- 2014
30. Inverse colloidal crystal membranes for hydrophobic interaction membrane chromatography
- Author
-
Anh T. Vu, Xinying Wang, S. Ranil Wickramasinghe, Bing Yu, Hua Yuan, Hailin Cong, Yongli Luo, and Jianguo Tang
- Subjects
Chromatography ,Antibodies, Monoclonal ,Humans ,Membranes, Artificial ,Filtration and Separation ,Antibodies, Monoclonal, Humanized ,Hydrophobic and Hydrophilic Interactions ,Porosity ,Analytical Chemistry - Abstract
Hydrophobic interaction membrane chromatography has gained interest due to its excellent performance in the purification of humanized monoclonal antibodies. The membrane material used in hydrophobic interaction membrane chromatography has typically been commercially available polyvinylidene fluoride. In this contribution, newly developed inverse colloidal crystal membranes that have uniform pores, high porosity and, therefore, high surface area for protein binding are used as hydrophobic interaction membrane chromatography membranes for humanized monoclonal antibody immunoglobulin G purification. The capacity of the inverse colloidal crystal membranes developed here is up to ten times greater than commercially available polyvinylidene fluoride membranes with a similar pore size. This work highlights the importance of developing uniform pore size high porosity membranes in order to maximize the capacity of hydrophobic interaction membrane chromatography.
- Published
- 2015
31. Synthesis of P(St-MMA-AA) Colloids and Application in Colloidal Crystals
- Author
-
Xiu Song Zhao, Jianguo Tang, Hailin Cong, Shu-Jing Yang, Li-Xin Zhang, and Bing Yu
- Subjects
endocrine system ,Materials science ,Band gap ,digestive, oral, and skin physiology ,technology, industry, and agriculture ,Analytical chemistry ,Emulsion polymerization ,Bragg's law ,Colloidal crystal ,Condensed Matter Physics ,complex mixtures ,Spectral line ,Electronic, Optical and Magnetic Materials ,body regions ,Crystallography ,Colloid ,Atom force microscopy ,Control and Systems Engineering ,Phase (matter) ,Materials Chemistry ,Ceramics and Composites ,Electrical and Electronic Engineering - Abstract
A series of monodispersed P(St-MMA-AA) colloids with diameters from 200 nm to 500 nm was synthesized successfully using emulsion polymerization. The corresponding colloidal crystals were fabricated and investigated. UV-Vis reflectance spectra showed that the band gaps of the obtained colloidal crystals accord well with Bragg law. The height, phase and spectrum 2D images of the obtained binary colloidal crystals were studied using different modes of atom force microscopy.
- Published
- 2011
32. Polymer–inorganic nanocomposite membranes for gas separation
- Author
-
Hailin Cong, Youqing Shen, Brian F. Towler, and Maciej Radosz
- Subjects
chemistry.chemical_classification ,Nanocomposite ,Chemistry ,Synthetic membrane ,Filtration and Separation ,Polymer ,Analytical Chemistry ,Membrane ,Chemical engineering ,Permeability (electromagnetism) ,Polymer chemistry ,Chemical stability ,Gas separation ,Selectivity - Abstract
Polymer–inorganic nanocomposite membranes present an interesting approach to improve the separation properties of polymer membranes because they possess properties of both organic and inorganic membranes such as good permeability, selectivity, mechanical strength, and thermal and chemical stability. The preparations and structures of polymer–inorganic nanocomposite membranes, their applicability to gas separation and separation mechanism are reviewed.
- Published
- 2007
33. Ionene-dynamically coated capillary for analysis of urinary and recombinant human erythropoietin by capillary electrophoresis and online electrospray ionization mass spectrometry
- Author
-
Yuanzong Li, Hailin Cong, Bing Yu, Feng Liu, and Huwei Liu
- Subjects
chemistry.chemical_classification ,Spectrometry, Mass, Electrospray Ionization ,Electrospray ,Chromatography ,Molecular Structure ,Polymers ,Capillary action ,Electrospray ionization ,Analytical chemistry ,Electrophoresis, Capillary ,Filtration and Separation ,Polymer ,Mass spectrometry ,Recombinant Proteins ,Polyelectrolyte ,Analytical Chemistry ,Quaternary Ammonium Compounds ,Capillary electrophoresis ,chemistry ,Erythropoietin ,medicine ,Humans ,medicine.drug - Abstract
In this article, a series of ionene polymers were synthesized and used to coat fused-silica capillaries for the separation of recombinant and urinary human erythropoietin (rhEPO and uEPO) standards by CE. The influence of the charge density of coatings on the separation of rhEPO and uEPO glycoforms was investigated. Then, we further studied the method for fast separation and detection of rhEPO and uEPO standards by CE-ESI-MS. The influence of several CE and MS operating parameters, such as the concentration of CE running buffer, applied external pressure, and the composition and flow rate of sheath liquid on CE-ESI-MS was studied. The results demonstrated that when the capillary was permanently coated with 6,6-ionene and the pH value of acetic acid-ammonium acetate running buffer was 4.80 and 5.50, respectively, a significantly reproducible separation was achieved for rhEPO and uEPO glycoforms. In the online CE-ESI-MS experiments, we not only achieved the online MS signal of uEPO, but also obtained baseline separation of three major rhEPO glycoforms successfully and reproducibly on the 6,6-ionene-coated capillaries. Furthermore, the standard mixture of rhEPO and uEPO was separated, and two incompletely resolved peaks that were identified to be rhEPO and uEPO by the unique MS "fingerprint" were obtained. Additionally, the molecular weight of rhEPO and uEPO were verified and compared to the results by MALDI-TOF-MS. It can be concluded that, in contrast to other indirect methods, the online CE-ESI-MS technique with the combination of the advantages of both CE and MS shows great potential for the separation and detection of rhEPO doping directly in competitive sports.
- Published
- 2005
34. Separation and detection of erythropoietin by CE and CE?MS
- Author
-
Hailin Cong, Feng Liu, Yuanzong Li, Huwei Liu, and Bing Yu
- Subjects
Electrospray ,Matrix-assisted laser desorption/ionization ,Chemical ionization ,Chromatography ,Capillary electrophoresis ,Isoelectric focusing ,Chemistry ,Electrospray ionization ,Gas chromatography–mass spectrometry ,Mass spectrometry ,Spectroscopy ,Analytical Chemistry - Abstract
For doping control, the standard method of testing recombinant human erythropoietin (rhEPO) is a combination of a blood test and a urine test. The blood test is based primarily on changes in blood parameters, and the urine test employs an immunoblotting assay that includes one isoelectric focusing (IEF) separation step, two blotting steps and luminescence detection, so the whole testing procedure is time-consuming and expensive. The present review summarizes the separation and the detection of rhEPO by capillary electrophoresis (CE) as well as by CE on-line coupled with electrospray ionization mass spectrometry (CE–ESI-MS). We demonstrate the usefulness of these approaches.
- Published
- 2005
35. Novel covalently coated diazoresin/polyvinyl alcohol capillary column for the analysis of proteins by capillary electrophoresis
- Author
-
Jianguo Tang, Peng Liu, Hailin Cong, Bing Yu, and Li-Xin Zhang
- Subjects
Capillary action ,Surface Properties ,Clinical Biochemistry ,engineering.material ,Biochemistry ,Polyvinyl alcohol ,Analytical Chemistry ,chemistry.chemical_compound ,Capillary electrophoresis ,Coating ,Organic chemistry ,biology ,Hydrogen bond ,Chemistry ,Cytochrome c ,Electrophoresis, Capillary ,Proteins ,Reproducibility of Results ,Chemical engineering ,Covalent bond ,Polyvinyl Alcohol ,engineering ,biology.protein ,Spectrophotometry, Ultraviolet ,Electroosmosis ,Azo Compounds ,Protein adsorption - Abstract
A novel method for the preparation of covalently linked capillary coatings of PVA was demonstrated using photosensitive diazoresin (DR) as coupling agents. Layer-by-layer self-assembly film of DR and PVA based on hydrogen bonding was first fabricated on the inner wall of capillary, then the hydrogen bonding was converted into covalent bonding after treatment with UV light through the unique photochemistry reaction of DR. The covalently bonded coatings suppressed basic protein adsorption on the inner surface of capillary, and thus a baseline separation of lysozyme, cytochrome c and BSA was achieved using CE. Compared with bare capillary or noncovalently bonded DR/PVA coatings, the covalently linked DR/PVA capillary coatings not only improved the CE separation performance for proteins, but also exhibited good stability and repeatability. Due to the replacement of highly toxic and moisture-sensitive silane coupling agent by DR in the covalent coating preparation, this method may provide a green and easy way to make the covalently coated capillaries for CE.
- Published
- 2012
36. RECENT DEVELOPMENT AND APPLICATION OF SOLID PHASE EXTRACTION MATERIALS.
- Author
-
Zhun Li, Bing Yu, Hailin Cong, Hua Yuan, and Qiaohong Peng
- Subjects
SOLID phase extraction ,MONOLITHIC reactors ,POLLUTANTS ,CHEMICAL preconcentration ,ANALYTICAL chemistry - Abstract
Recently, the solid phase extraction technology has received considerable attention considering serious environmental problems and much more contaminants present in the samples at trace level that is different to be analyzed. During the whole process of analyzing sample, the preconcentration of sample is the most complicated and significant step, which typically spend much time, affecting the analysis efficiency and accuracy of results to a large extent. Obviously, the sample pretreatment has become an obstacle that prevents us from improving analysis efficiency. If this problem cannot be resolved, the overall efficiency of analytical work will not be enhanced, even using the advanced analysis devices. As a result, increasing the success rate of sample pretreatment is especially necessary. Now, this review mainly represents the current development of solid phase extraction from the following aspects: (1) the type of adsorbent, including organic, polymer materials; (2) the different mode of separation, such as solid phase extraction, molecule imprinting solid phase extraction, solid phase microextraction, dispersive solid phase extraction, matrix solid phase dispersion, magnetic solid phase extraction, microchip solid phase extraction, stir bar sorptive extraction, immunoaffinity solid phase extraction, monolith solid phase extraction; (3) the practical applications of various solid phase extraction methods are also have been described in this article. [ABSTRACT FROM AUTHOR]
- Published
- 2017
37. Recent progress in preparation and application of microfluidic chip electrophoresis.
- Author
-
Xiaodan Xu, Hua Yuan, Qiaohong Peng, Chao Tian, Hailin Cong, and Bing Yu
- Subjects
MICROCHIP electrophoresis ,ELECTROPHORESIS ,MICROFABRICATION ,ANALYTICAL chemistry ,DERIVATIZATION ,POLYDIMETHYLSILOXANE ,POLYSTYRENE - Abstract
Since its discovery in 1990, microfluidic chip electrophoresis (MCE) has allowed the development of applications with small size, fast analysis, low cost, high integration density and automatic level, which are easy to carry and have made commercialization efficient. MCE has been widely used in the areas of environmental protection, biochemistry, medicine and health, clinical testing, judicial expertise, food sanitation, pharmaceutical checking, drug testing, agrochemistry, biomedical engineering and life science. As one of the foremost fields in the research of capillary electrophoresis, MCE is the ultimate frontier to develop the miniaturized, integrated, automated all-in-one instruments needed in modern analytical chemistry. By adopting the advanced technologies of micro-machining, lasers and microelectronics, and the latest research achievements in analytical chemistry and biochemistry, the sampling, separation and detection systems of commonly used capillary electrophoresis are integrated with high densities onto glass, quartz, silicon or polymer wafers to form the MCE, which can finish the analysis of multi-step operations such as injection, enrichment, reaction, derivatization, separation, and collection of samples in a portable, efficient and super high speed manner. With reference to the different technological achievements in this area, the latest developments in MCE are reviewed in this article. The preparation mechanisms, surface modifications, and properties of different materials in MCE are compared, and the different sampling, separation and detection systems in MCE are summarized. The performance of MCE in analysis of fluorescent substance, metallic ion, sugar, medicine, nucleic acid, DNA, amino acid, polypeptide and protein is discussed, and the future direction of development is forecast. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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