JOURNAL OF SEPARATION SCIENCE
·
2016
·Vol. 40
·期 4
·954-961
·
IF 2.741
Yilin Li,Tao Bao,Zilin Chen
In this work, we developed a capillary column modified with zeolitic imidazolate framework-8 as a novel stationary phase for open-tubular capillary electrochromatography. To immobilize zeolitic imidazolate framework-8 onto the inner surface of silica capillary, a bio-inspired polydopamine functionalization was used to functionalize the capillary surface with polydopamine. First, a polydopamine layer was assembled inside the capillary. Second, due to noncovalent adsorption and covalent reaction ability, polydopamine could attract and anchor zeolitic imidazolate framework-8 onto the inner surface of capillary. It has been demonstrated that zeolitic imidazolate framework-8 was successfully grafted on the inner wall of the capillary by scanning electron microscopy, and Fourier transform infrared spectroscopy. The electro-osmotic flow characteristics of capillaries were also investigated by varying the pH value and acetonitrile content of mobile phase. The zeolitic imidazolate framework-8 coating not only increased the phase ratio of open-tubular column, but also improved the interactions between tested analytes and the stationary phase. Three groups of isomers including acidic, basic, and neutral compounds were well separated on the zeolitic imidazolate framework-8 bonded column, with theoretic plate numbers up to 1.9 × 10 5 N for catechol. The repeatability of the prepared columns was also studied, and the relative standard deviations for intra- and interday runs were less than 5%.
研究领域:
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2016
·
IF 3.926
Tao Bao,Pingxiu Tang,Deying Kong,Zhenkun Mao,Zilin Chen
Covalent-organic frameworks (COFs) are attractive materials for their fascinating properties, such as rigid structures, exceptional thermal stabilities, low densities, and permanent porosity with specific surface areas, which indicate potential for application in chromatography similar to related metal-organic frameworks (MOFs). However, the utilization of COFs in analytical chemistry is far behind as compared to that of the MOFs due to the challenging work of their immobilization. Here, we have successfully demonstrated the growth of the boron COF-5 on the inner wall of the fused silica capillary by a developed polydopamine-supported method. Combined with the layer-by-layer strategy, multilayer COF-5-coated capillary was obtained. The formation of COF-5 on polydopamine-coated substrate has been confirmed by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction. A novel stationary phase of COF-5 was developed on the basis of successful growth of COF-5 on polydopamine for open-tubular capillary electrochromatography (OT-CEC). Baseline separation of neutral, acidic and basic analytes was achieved on multilayer COF-5-coated capillary column. The fabricated capillary columns showed high column efficiency (154,060 plates/m for methylbenzene), excellent stability and repeatability. The precision (relative standard deviation (RSD), n = 3) of retention time, peak height, and peak area for tested neutral compounds were in the range of 1.2–1.3%, 1.8–4.2%, and 0.9–2.4%, respectively. To the best of our knowledge, it was the first demonstration that COF-5 was developed as a novel stationary phase.
研究领域:
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2016
·
IF 3.926
Zhenkun Mao,Zilin Chen
A novel monolithic column with ionic liquid and styrene-modified bifunctional group was prepared for capillary electrochromatography (CEC) by in situ copolymerization in a ternary porogenic solvent. Ionic liquid (1-allyl-methylimidazolium chloride, AlMeIm + Cl − ) and styrene served as the bifunctional monomer, while ethylene dimethacrylate (EDMA) was used as the cross-linker. The monomer of AlMeIm + Cl − was introduced as anion-exchange group, while styrene as hydrophobic and aromatic group; the similar conjugated structure in AlMeIm + Cl − and styrene was beneficial for offeing obvious synergistic effect. The bifunctional stationary phase possessed powerful selectivity for the separation of neutral compounds, acidic analytes and phenols. The highest column efficiency was 2.70 × 10 5 plates m −1 (theoretical plates, N) for toluene. A relatively strong electroosmotic flow (EOF) was obtained in a wide range of pH values from 2.0 to 12.0, which could successfully achieve the rapid separation of the analytes within 10 min. The proposed monolithic column was characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR). The results indicated that the resultant monolithic column had good permeability and excellent mechanical stability. Good reproducibility was obtained with relative standard deviations (RSDs) of the retention time in the range of 0.24–0.47% and 0.81–2.17% for run-to-run (n = 5) and day-to-day (n = 5), while 1.09–2.70% and 0.98–1.70% for column-to-column (n = 3) and batch-to-batch (n = 3), respectively. The combination of AlMeIm + Cl − and styrene was a promising option in the fabrication of the organic polymer monolithic column.
研究领域:
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROPHORESIS
·
2016
·
IF 2.482
Qishu Qu,Han Xuan,Kehua Zhang,Yi Ding,Qin Xu
In this work, open-tubular capillary column coated with zeolite imidazolate framework-8 (ZIF-8) nanocrystals was prepared by a layer-by-layer method. The coating was formed by growing ZIF-8 nanocrystals on either bare fused silica capillary wall or the capillary column premodified with amino groups. The shape and the thickness of the coating formed by using these two methods were almost the same. However, the coverage of the ZIF-8 crystals on the bare fused silica capillary wall was higher than that on the capillary column premodified with amino groups. The ZIF-8 coated capillary column was evaluated for open-tubular capillary electrochromatography. The effect of pH value, buffer concentration, and applied voltage on the separation of phenols was investigated. Good separation of nine phenolic isomers was achieved because of the strong interaction between unsaturated Zn sites and phenols. The column performance for o -nitrophenol was as high as 208 860 plates m −1 . The run-to-run, day-to-day, and column-to-column reproducibility of retention time and resolution for p -nitrophenol and o -nitrophenol were very good with RSDs of less than 6.5%.
研究领域:
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHROMATOGRAPHIA
·
2024
·
IF 1.2
Shao Xiaozhen,Xu Guangfu,Chen Jiaquan,Miao Pandeng,Yang Ke,Du Yingxiang,Yu Tao
Metal–organic frameworks (MOFs) have a wide range of applications in separation and analytical sciences due to their unique structures. MIL-100(Fe) was immobilized on the inner wall of the capillary column based on the immobilized cysteine (Cys)-triggered in situ growth (ICISG) strategy. By applying this column to capillary electrophoresis, a novel enantioselective separation system based on MIL-100(Fe) nanomaterial was established. By utilizing lactobionic acid (LA) as the chiral selector and optimizing the experimental conditions such as buffer pH, LA concentration and the methanol addition ratio, the CEC system demonstrated a significantly enhanced enantioseparation ability for six basic drugs. The modified capillary column was characterized by scanning electron microscope (SEM), energy-dispersive X-ray spectroscope (EDS) and X-ray diffractometer. The experimental results showed that MIL-100(Fe) was successfully grown on the inner wall of the capillary column. In the present study, the repeatability of the coated column was investigated and the relative standard deviations (RSDs) of the resolution and the migration time for intra-day, inter-day and inter-column were within 8%, proving the good repeatability of the coated column.
研究领域:
分析化学
·
药物科学
✓ 已验证
产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 12
·1-8
·
IF 6.232
Ding Wen,Ma Mingxuan,Du Yingxiang,Chen Cheng,Ma Xiaofei
An in situ zeolite imidazole metal organic framework-90 (ZIF-90) modified capillary was prepared via the method of solvothermal synthesis. The coating of ZIF-90 was characterized by scanning electron microscopy, energy-dispersive X-ray spectrometry, and EOF. Capillary electrochromatography–based enantioseparation of the basic drugs propranolol (PRO), metoprolol (MET), atenolol (ATE), bisoprolol (BIS), and sotalol (SOT) was performed using lactobionic acid (LA) as the chiral selector. Compared with an uncoated silica capillary, the resolutions are greatly improved (PRO 1.40 → 3.23; MET 1.07 → 3.19; ATE 1.07 → 3.15; BIS 1.16 → 3.41; SOT 1.00 → 2.79). Effects of buffer pH values, proportion of organic additives, concentration of lactobionic acid, and applied voltage were investigated.
Schematic presentation of the preparation of zeolitic imidazolate framework-90 (ZIF-90) modified capillary (ZIF-90@capillary) for enantioseparation of drug enantiomers. The capillary was applied to construct capillary electrochromatography system with lactobionic acid for enantioseparation of basic chiral drugs.
研究领域:
分析化学
·
药物分析
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2019
·
IF 3.858
Jiannan Sun,Shiwei Yang,Heyong Cheng,Yuanchao Wang,Jinhua Liu
Further development of capillary electrochromatography (CEC) is to some extent restricted by column technology. Packed capillary columns are most commonly used in CEC because of higher sample capacity and higher sensitivity than open tubular columns, and better reproducibility and uniformity than monolithic columns. Fritting is the core component for the fabrication of packed capillary columns. Therefore various fritting technologies attract continuous attention from analytical community. A convenient fritting method was developed in this study. In contrast to the reported single-particle fritting, this method applies a multi-particle fritting technology to hold stationary phase in capillary columns. Several large porous particles smaller than the column internal diameter were tapped in and immobilized in inlet and outlet of the packing material bed due to direct and indirect keystone effect. Except the smallest permeability by the sintered frit and the lowest breaking pressure by the single-particle frit, EOF mobility and peak dispersion of the multi-particle frit were at the same levels with the formers. In addition, all the three frits avoided bubble formation. It demonstrated that the multi-particle frits met the general requirements of permeability, mechanical resistance and efficiency for packing capillary microcolumns as well as the sintered frits and the single-particle frits. Thus, peak efficiency around 4.3 μm plate height (approximately 232,560 plates per meter) was obtained by multi-particle fritted capillary columns with electrokinetic packing, compared to 6.5 μm plate height by single-particle fritted columns with slurry pressure packing. In particular, the multi-particle fritting was simpler, faster, and more reproducible than the sintered fritting, and the multi-particle fritting was suitable to pack capillary columns of various capillary bore sizes owing to rich commercial resources of fritting particles of various diameters. Multi-particle fritted columns offered satisfactory run-to-run and column-to-column reproducibilities for retention factor, plate height and peak area (precisions of 4.1–9.3% for 10 replicated columns, and precisions of 0.9–3.1% for 30 replicated trials). They also had consistent CEC performance (differences of 1.1–3.9% between the first and 31 st day) during a lifetime more than one month. Application examples in packing capillary columns of 75 and 100 μm i.d. and CEC analysis of sixteen polycyclic aromatic hydrocarbons prove the diversity and reliability of the multi-particle fritting in column technology.
研究领域:
分析化学
·
分离科学
·
色谱技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2017
·Vol. 184
·期 4
·1169-1176
·
IF 4.58
Kong Deying,Bao Tao,Chen Zilin
The covalent organic framework LZU1 (Lan Zhou University-1) is one of the imine-based covalent organic frameworks (COFs) that possesses attractive properties such as structural regularity, stability and good porosity. This work reports on the in-situ synthesis of COF-LZU1 on the inner walls of capillary column for open-tubular capillary electrochromatography (OT-CEC). The fused-silica capillary was first modified with 3-aminopropyltriethoxysilane and glutaraldehyde. Epitaxial growth of COF-LZU1 on the inner walls was accomplished by Schiff base reaction. The formation of COF-LZU1 was confirmed by SEM and FT-IR. The COF-LZU1 coating increases the interactions between analytes and coating, which remarkably improves the CEC separation selectivity of neutral analytes, amino acids and nonsteroidal anti-inflammatory drugs. The COF-LZU1-modified column exhibits good stability and repeatability. The precisions (relative standard deviations) for intra-day, inter-day and column-to column are <1.6%, 5.6% and 6.8%, respectively. Hence, the imine-based COFs represent attractive stationary phase for application in CEC separations.
Covalent organic framework (COF-LZU1) was in situ synthesized on the inner wall of a capillary column for electrochromatographic separation of nonsteroidal drugs and amino acids.
研究领域:
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2016
·
IF 3.926
Li-Shun Zhang,Pei-Yao Du,Wen Gu,Qing-Li Zhao,Yan-Ping Huang,Zhao-Sheng Liu
A new lanthanide metal-organic frameworks NKU-1 have successfully incorporated into poly (BMA- co -EDMA) monolith and evaluated by capillary electrochromatography (CEC). Lanthanide metal-organic frameworks [Eu 2 (ABTC) 1.5 (H 2 O) 3 (DMA)] (NKU-1) were synthesized by self-assembly of Eu(III) ions and 3,3′,5,5′-azo benzene tetracarboxylic acid ligands have been fabricated into poly(BMA- co -EDMA) monoliths. 1-Butyl-3-methylimidazolium tetrafluoroborate and N , N -dimethylformamide were developed as binary porogen obtaining homogeneous dispersibility for NKU-1 and high permeability for monolithic column. The successful incorporation of NKU-1 into poly(BMA- co -EDMA) was confirmed and characterized by FT-IR spectra, scanning electron microscopy, X-ray diffraction, energy dispersive spectrometer area scanning, and transmission electron microscopy. Separation ability of the NKU-1-poly (BMA- co -EDMA) monoliths was demonstrated by separating four groups of analytes in CEC, including alkylbenzenes, polycyclic aromatic hydrocarbon, aniline series and naphthyl substitutes. Compared with bare monolithic (column efficiency of 100,000 plates/m), the NKU-1-poly (BMA- co -EDMA) monoliths have displayed greater column efficiency (maximum 210,000 plates/m) and higher permeability, as well as less peak tailing. The results showed that the NKU-1-poly (BMA- co -EDMA) monoliths are promising stationary phases for CEC separations.
研究领域:
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2018
·
IF 3.716
Zhenkun Mao,Tao Bao,Zhentao Li,Zilin Chen
A novel ionic liquid (1-allyl-methylimidazolium chloride, AlMeIm + Cl − ) polymer monolith poly(ionic liquid- co -ethylene dimethacrylate) incorporated with zeolitic imidazolate framework-8 (ZIF-8-poly(IL- co -EDMA)) was firstly synthesized as stationary phases of monolithic column for capillary electrochromatography by one-step copolymerization. Incorporation of ZIF-8 into ionic liquid polymer monolith evidently enhanced the separation selectivity for four alkylbenzenes in reversed phase capillary electrochromatography (CEC), due to the synergistic effect derived from the same imidazole ring structure of ionic liquid and organic ligands of ZIF-8. Meanwhile, electroosmotic flow (EOF) was generated by ionic liquid in a wide range of pH values from 2.0 to 12.0. The resultant monolithic columns were characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR). The results indicated that the prepared monolithic columns had good permeability and mechanism stability. The resultant monolithic columns were applied for the separation of neutral compounds, anilines and phenols. The highest column efficiency was 2.07 × 10 5 plates m −1 (theoretical plates, N) for toluene. Under optimal conditions, reproducibility was obtained with relative standard deviations (RSDs) of the retention time for run-to-run, day-to-day, column-to-column and batch-to-batch were in the range of 1.58 − 3.19%, 1.92 − 3.87%, 3.84 − 4.96% and 2.63 − 4.33%, respectively. Incorporation ZIF-8 into ionic liquid polymer monolith was a promising way for the application of new materials in the fabrication of novel monolithic columns.
研究领域:
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROPHORESIS
·
2021
·Vol. 42
·期 24
·2664-2671
·
IF 3.535
Wei Zhou,Xinhong Yu,Yikun Liu,Wenqi Sun,Zilin Chen
Enhancing the specific surface area of stationary phase is important in chromatographic science, especially in open-tubular column in which the coating only exists on the inner surface. In this work, a porous layer open-tubular (PLOT) column with stationary phase of styrene and itaconic acid-copolymerized polymer was developed. Thermal-initiated polymerization method with strategies like controlling the ratio of reaction reagents to solvents and reaction time, confinement by the narrow inner diameter of capillary were used for preparing the stationary phase with uniform structure and relatively thick layer. Due to the high separation efficiency and capacity, the PLOT column was used for capillary electrochromatography (CEC) separation of multiple groups of analytes like alkylbenzenes, phenyl amines, phenols, vanillins, and sulfonamides with theoretical plates (N) up to 1,54,845 N/m. In addition, due to high permeability of the CEC column and large electroosmotic flow mobility generated by abundant carboxyl groups in the coating material, the PLOT-CEC column was successfully coupled with mass spectrometry (MS) through a sheath flow interface. The developed PLOT-CEC-MS method was used for the analysis of antiseptics like parabens and herbicides like pyridines.
研究领域:
分析化学
·
分离科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2015
·
IF 4.169
Tao Bao,Juan Zhang,Wenpeng Zhang,Zilin Chen
Much attention is being paid to applying metal–organic frameworks (MOFs) as stationary phases in chromatography because of their fascinating properties, such as large surface-to-volume ratios, high levels of porosity, and selective adsorption. HKUST-1 is one of the best-studied face-centered-cubic MOF containing nano-sized channels and side pockets for film growth. However, growth of HKUST-1 framework inside capillary column as stationary phase for capillary electrochromatography is a challenge work. In this work, we carry out the growth of HKUST-1 on the inner wall of capillary by using liquid-phase epitaxy process at room temperature. The fabricated HKUST-1@capillary can be successfully used for the separation of substituted benzene including methylbenzene, ethylbenzene, styrene, chlorobenzene, bromobenzene, o -dichlorobenzene, benzene series, phenolic acids, and benzoic acids derivates. High column efficiency of 1.5 × 10 5 N/m for methylbenzene was achieved. The formation of HKUST-1 grown in the capillary was confirmed and characterized by scanning electron microscopy images, Fourier transform infrared spectra and X-ray diffraction. The column showed long lifetime and excellent stability. The relative standard deviations for intra-day and inter-day repeatability of the HKUST-1@capillary were lower than 7%.
研究领域:
分析化学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）