ANALYTICA CHIMICA ACTA
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2018
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IF 5.123
Yujie Zhang,Qiaoqi Li,Hui Zhong,Shouyong Zhou,Yijiang Zhao,Mingliang Zhang,Haifeng Han,Hongdeng Qiu
Aromatic stationary phases showing complementary selectivity to their alkyl counterparts are extremely useful for certain challenging separation tasks. Herein, a series of polar-embedded aryl stationary phases were synthesized from reactive derivatives of large polycyclic aromatic hydrocarbons (PAHs), including anthracene (three-ring, catacondensed), pyrene (four-ring, pericondensed) and triphenylene (four-ring, fully-benzenoid). These PAHs were functionalized with hydroxymethyl group (PAH-CH 2 OH), then catalytically converted to carbamates (PAH-CH 2 OC(=O)NH-R) using isocyanate , and finally covalently grafted onto silica to produce corresponding carbamate-embedded PAH stationary phases. To gain insight into the connection and difference among the attached species, the chromatographic behaviors of these new adsorbents were systematically evaluated in terms of surface coverage, hydrophobic and aromatic features, shape selectivity and charge-transfer property, using different classes of analytes, such as alkylbenzenes , PAH congeners and isomeric multi-substituted benzenes, and the results were further compared with conventional octadecyl ones (C18). The relationships between the shape selectivity and the surface chemistry revealed unique behavioral patterns of theses immobilized conjugated ligands, as well as marked differences amongst them, which formed sharp contrast to the case of C18. The effects of temperature and mobile phase compositions on the shape selectivity were further studied. The charge-transfer characteristics demonstrated the great potential of such polar-embedded PAH materials for highly selective separation of electron-deficient compounds through electron donor-acceptor complexation.
研究领域:
分析化学
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材料科学
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DOI
PubMed
高影响因子
ACS Applied Polymer Materials
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2022
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IF 4.855
Li Gao,Huiying Zuo,Aikun Han,Yaming Sun,Xue Ma,Lijun He,Wenjie Zhao
Two versions of reversed-phase/hydrophilic interaction mixed-mode core–shell stationary phases for high-performance liquid chromatography using porous organic polymers as the shell material were investigated. The stationary phase named SiO2@CTPCC-TPB using triazine-triphenylbenzene-based porous organic polymers as the shell material has been reported previously. To regulate chromatographic performance, heptazine–biphenyl moieties with fewer benzene rings and higher nitrogen content were used as organic building blocks to grow a porous shell on the surface of silica to acquire a core–shell stationary phase, namely, SiO2@CHPCy-DB. Various techniques were used to characterize the developed core–shell microsphere, and nonpolar/polar solutes were utilized as probes to investigate the chromatographic behavior of the stationary phase. The results revealed that SiO2@CHPCy-DB exhibited reversed-phase/hydrophilic interaction mixed-mode with multiple retention mechanisms. Meanwhile, the separation behavior of the two homemade columns and a commercial column was compared to assess the role of the building blocks in porous organic polymers in regulating and improving separation. The successful determination of drugs of abuse in urine via the SiO2@CHPCy-DB column indicated its potential for the determination of trace analytes in complex samples.
研究领域:
分析化学
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材料科学
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色谱技术
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DOI
高影响因子
JOURNAL OF SEPARATION SCIENCE
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2014
·Vol. 37
·期 22
·3268-3275
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IF 2.594
Zhifen Deng,Junwei Liu,Chenchen Hu,Liu Yang,Huifang Du,Kai Hu,Yanjie Huang,Xiaoqing Yang,Qiong Jiang,Shusheng Zhang
Two new kinds of alanine-substituted calix[4]arene stationary phases of 5,11,17,23- p-tert- butyl-25,27-bis( l -alanine-methylester- N -carbonyl-methoxy)-26,28-dihyroxycalix[4]arene-bonded silica gel stationary phase (BABS4) and 5, 11, 17, 23- p-tert -butyl-25,26,27,28-tetra( l -alanine-methylester- N -carbonyl-methoxy)-calix[4]arene-bonded silica gel stationary phase (TABS4) were prepared and characterized in the present study. They were compared with each other and investigated in terms of their chromatographic performance by using polycyclic aromatic hydrocarbons, disubstituted benzene isomers, and mono-substituted benzenes as solute probes. The results indicated that both BABS4 and TABS4 exhibited multiple interactions with analytes. In addition, the commonly used Tanaka characterization protocol for the evaluation of commercially available stationary phases was applied to evaluate the properties of these two new functionalized calixarene stationary phases. The Tanaka test results were compared with Zorbax Eclipse XDB C 18 and Kromasil phenyl columns, respectively. BABS4 has stronger hydrogen-bonding capacity and ion-exchange capacity than TABS4, and features weaker hydrophobicity and hydrophobic selectivity. Both of them behave similarly in stereoselectivity. Both BABS4 and TABS4 are weaker than C 18 and phenyl stationary phases in hydrophobicity and hydrophobic selectivity.
研究领域:
分析化学
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色谱学
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DOI
高影响因子
MICROCHEMICAL JOURNAL
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2021
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IF 4.821
Zuoling Zhang,Min Xia,Pengfei Huang,Bin Di,Mengxiang Su
New stationary-phase materials are of great interest for use in hydrophilic interaction liquid chromatography (HILIC), a relatively new technique capable of separating highly polar compounds. In this study, a new strategy was established to prepare a novel Sil-Bac stationary phase by bonding bacitracin to silanised silica particles using hexamethylene diisocyanate as a spacer arm. The obtained material was characterised by Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller analysis, transmission electron microscopy (TEM), and elemental analysis. The network layers observed through TEM and change in specific surface area from 315.0820 to 169.6758 m 2 ·g −1 after modification reflected the addition of bacitracin. The chromatographic behaviour of the Sil-Bac column showed that it can be used for HILIC. The influence of the chromatographic conditions on substance retention was explored by varying the acetonitrile content, column temperature, buffer concentration, and pH of the mobile phase. Using cytosine, uracil, nicotinamide, and isonicotinic acid as probes, the Sil-Bac column was demonstrated to have acceptable repeatability and stability, with a relative standard deviation of the retention time in the ranges of 0.05–0.18% for intra-day precision ( n = 3) and 0.16–3.28% for inter-day precision ( n = 3). Finally, the stationary phase was applied in separating basic nucleosides, water-soluble vitamins, and amino acids. A variety of bases and nucleosides could be separated within 7 min in a mobile phase of ACN/ammonium acetate (pH 3.0) = 90/10 (v/v), T = 30 °C. The Sil-Bac column was also compared with three commercial columns, and the results indicated that the analytes retained on the Sil-Bac column showed better retention and selectivity from an overall view. This novel stationary phase has a good separation ability and selectivity in HILIC mode and provides new ideas for the separation of polar compounds.
研究领域:
分析化学
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色谱技术
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DOI
高影响因子
TALANTA
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2018
·
IF 4.244
Quan Wang,Shigang Shen
A novel porous monolithic column was synthesized via in situ free-radical polymerization within a stainless steel column (50 × 4.6 mm i.d.) by using triallyl isocyanurate and methyl methacrylate as co-monomers, ethylene glycol dimethacrylate as a crosslinking agent, 1,4-butanediol, 1- dodecanol , and N, N-dimethylformamide as tri-porogens, and azobisisobutyronitrile as an initiator. The optimized monolithic columns were investigated by scanning electron microscopy, a nitrogen absorption-desorption apparatus, and mercury intrusion porosimetry. The effect of mobile phase composition and temperature on chromatographic behavior was studied in detail as well. The results showed that homemade monolithic columns not only have relative uniform porosity structure, low back pressure, and high thermal stability, but also show high column efficiency, the theoretical plates number of the new polymer monolithic column exceeded 31,000 plates m −1 . Good resolution was achieved for HPLC separation of small molecules, including polycyclic aromatic hydrocarbons , isomers of phenols, and the Chinese herbal medicine notoginseng. Methodological validation of six drugs in notoginseng show that correlation coefficients of the linear regressions were in the range of 0.9989–0.9997; the value of relative standard deviation for precision were in the range of 1.37–4.21% for intra-day and 0.34–5.31% for inter-day, respectively; the values of accuracy expressed by recovery were in the range of 100.57–102.51%, 95.18–102.68%, 101.61–102.82%, 100.94–102.40%, 100.99–103.15% and 99.49–103.91% for the six drugs in order, respectively. Taking aromatic hydrocarbons as samples, the relative standard deviation values of the run-to-run (n = 5) and column-to-column (n = 5) based on peak area were < 2.01% and 2.39%, and two RSDs based on retention time were < 2.56% and 2.23%, respectively. The result showed that the polymer monolithic column has good separation ability and high permeability for small molecular substances.
研究领域:
分析化学
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药学
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材料科学
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PubMed
高影响因子
MICROCHEMICAL JOURNAL
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2019
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IF 3.206
Tiantian Si,Xiao Song,Licheng Wang,Yong Guo,Xiaojing Liang,Shuai Wang
A hydrophobically associating polyacrylamide (HAPM)-coated silica packing (HAPM@silica) as a novel stationary phase was synthesized by a simple thermal immobilization to separate multiple polar compounds for the first time. The successful immobilization of HAPM on the silica support was confirmed by elemental analysis, scanning electron microscopy (SEM) and the Brunauer–Emmett–Teller (BET). The thickness of HAPM coating is crucial and the one-layer HAPM@silica stationary phase was demonstrated the highest separation efficiency. Compared with the bare silica and amino modified silica, the new stationary phase showed better separation performance for multiple polar compounds such as bases, alkaloids, carbohydrates and amino acid compounds under the experimental conditions. The chromatographic behaviors were evaluated by investigating the effects of acetonitrile content, water content, mobile phase pH on separation. A typical hydrophilic interaction liquid chromatography (HILIC) retention feature of HAPM based column was observed at the low percentage of water content. The packing material also showed excellent chromatographic repeatability with intraday RSDs of the retention time of five bases less than 0.46% ( n = 10) and interday RSDs less than 1.45% ( n = 5). In summary, the new chromatographic material can be used for a feasible option for analysis of polar compounds.
研究领域:
分析化学
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色谱学
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材料科学
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DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
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2022
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IF 4.601
Yao Sun,Zhi'an Sun,Chaozhan Wang,Yinmao Wei
Aromatic phase, as one type of reversed-phase stationary phases, shows complementary selectivity to the n -alkyl counterparts especially for certain challenging separation tasks. However, effect of phenyl numbers in aromatic ligands on retention behaviors has rarely been addressed compared with the alkyl stationary phases. To illustrate the issue, a series of polyphenyl stationary phases were facially prepared via the coupling chemistry of isocyanate with amine, including aniline (π 1 ), 4-aminobiphenyl (π 2 ), 4-amino- p -terphenyl (π 3 ) and [1,1′:4′,1′':4′',1′''-quaterphenyl]-4-amine (π 4 ), respectively. The chromatographic behaviors of the new stationary phases as well as the traditional C18 were systematically compared in terms of retention mode, hydrophobic and aromatic selectivity, shape selectivity and π-π interaction by various analytes, including alkylbenzenes , polycyclic aromatic hydrocarbons congeners and substituted benzenes with electron-withdrawing groups. Due to the homologous structure of four polyphenyl ligands, the hydrophobic selectivity, aromatic selectivity and shape selectivity of stationary phases increase with phenyl numbers in the bonded polyphenyl ligands, whereas the increment becomes insignificant from U-π 3 to U-π 4 . This phenomenon is explained by the insertion degree of analytes in the polyphenyl ligand brushes. Compared with the homemade C18, the polyphenyl phases indicate insignificant changes of shape selectivity with temperature. Notably, the new polyphenyl phases demonstrate the great selective separation towards the electron-deficient compounds through the π-π interaction. These findings make up for the understanding of the retention behavior of aromatic stationary phases.
研究领域:
色谱学
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分析化学
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材料科学
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产品关联
DOI
PubMed
高影响因子
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