CHROMATOGRAPHIA
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2016
·Vol. 79
·期 19
·1263-1269
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IF 1.332
Wang Liang,Wu Minghuo,Wang Qixue,Zhan Jingjing,Chen Hongbo
Polyethylenimine (PEI) and 2,4,6,8-tetramethyl-2,4,6,8-tetrakis(propyl glycidyl ether)cyclotetrasiloxane (POSS–epoxy) were used as precursors for the preparation of organic-silica hybrid monolithic columns (PEI–POSS monolith) via epoxy–amine ring-opening polymerization (ROP). The high density of amine groups in PEI provides rich chromatographic interaction sites for the polar or acidic analytes in hydrophilic interaction (HILIC) and weak anion exchange (WAX) mechanisms. The column preparation conditions, such as the porogens, solvent and reaction temperature, were systematically investigated according to the morphology, permeability and column efficiency. The separation mechanisms of HILIC and WAX were evaluated with neutral polar compounds and halogen benzoic acids. Owing to the existence of reactive amine groups on the matrix surface, the PEI–POSS monolith is also an ideal starting material for the preparation of HILIC or strong anionic exchange (SAX) stationary phases by modification. The modification of PEI–POSS monoliths with iodomethane or bromoacetic acid via the nucleophilic substitution reaction could achieve the retention mechanisms of SAX or zwitterionic HILIC, respectively.
研究领域:
分析化学
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材料科学
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Journal of Pharmaceutical Analysis
·
2026
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IF 8.9
Yangrui Zhang,Yizhen Liu,Yangyang Chen,Chen Guo,Fengting Ou,Junhuan Lin,Hanmeng Guo,Tao Ke,Lushan Yu
The molecular complexity of active pharmaceutical ingredients (APIs) has increased over recent decades, with production largely relying on microbial processes such as fermentation. However, these processes introduce non-therapeutic protein impurities. Accurate quantification of protein impurities in APIs is critical, as underestimation risks safety and efficacy, while overestimation leads to costly over-purification. Here, we evaluated five conventional protein assays with diverse standards and found their accuracy compromised by protein structural diversity. To deconstruct the mechanism of this limitation, we examined the Bradford assay as a case study. Machine learning models trained on data from over 140 standards revealed that, beyond the known roles of basic and aromatic residues, other amino acids exert positive or negative effects on the Bradford assay response—as predicted by Lasso regression and validated with five designed peptides. Together with molecular docking and interaction analysis, which identified electrostatic interactions as the primary driving force, these findings collectively account for the inherent bias of such structure-dependent assays. The systematic evaluation and mechanistic insight prompted us to develop a hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry (HILIC-MS/MS) method for amino acid analysis, enabling accurate protein quantification at ppm levels in matrices. Applied to eight commercial APIs, the method revealed substantial variation in protein residue levels (9.53–5570 ppm). By providing precise measurement of protein impurities in small-molecule APIs, this study helps ensure drug safety and efficacy at no excessive purification costs, while also offering insights into the molecular mechanisms underlying the Bradford assay.
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JOURNAL OF CHROMATOGRAPHY A
·
2025
·
IF 4
Xingyun Zhao,Chengxiao Zhao,Rongfang Wu,Jiangyan Jin,Xiaojian Liu,Zhenwei Zhang,Siyu Yang,Ke Li,Zhenyu Li,Xuemei Qin
The development of core-shell materials for achieving more efficient and rapid chromatographic separations has remained a key objective in separation science. In this study, monodisperse SiO 2 particles (2–4 µm in diameter) were utilized to fabricate core-shell spheres through a combined approach involving a modified sol-gel process and a biphasic system. The synthesis employed 1,6-bis(triethoxysilyl) hexane (BTMSH), 1,2-bis(triethoxysilyl) ethane (BTEE) as a bridging agent with cetyltrimethylammonium bromide (CTAB) acting as a co-template. Notably, the shell thickness could be precisely tailored within the range of 70∼300 nm through systematic optimization of stirring rate, solvent selection, and silica precursor type. The separation of aromatics analytes was evaluated and that baseline separation was achieved for both molecules on all the columns packed n -octadecyltrichlorosilane modified core-shell silica particles with tunable shell thickness. Column efficiencies up to ∼168, 325 plates m -1 were achieved for pyrene on the CS X-E -C18 column ( n -octadecyltrichlorosilane modified core-shell silica). In addition, a hydrophilic interaction liquid chromatography (HILIC) core-shell stationary phase that amide modified core shell silica was prepared (named as CS X-E -AM) via an improved polymerization coating approach and applied for oligosaccharides separation. The results demonstrated that the core-shell spheres were prepared with tailored shell structure and exhibited that the column was stable and could meet the requirement for HPLC separation.
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
PubMed
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2024
·Vol. 25
·期 17
·9465
·
IF 4.9
Xingyun Zhao,Yifan Niu,Chengxiao Zhao,Zhenyu Li,Ke Li,Xuemei Qin
There are great challenges in the field of natural product isolation and purification and in the pharmacological study of oligosaccharide monomers. And these isolation and purification processes are still universal problems in the study of natural products (NPs), traditional Chinese medicine (TCM), omics, etc. The same polymer-modified materials designed for the special separation of oligosaccharides, named Sil-epoxy-PEI and Sil-chloropropyl-PEI, were synthesized via two different methods and characterized by scanning electron microscopy combined with energy spectrum analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, zeta potential as well as surface area analysis, etc. Several nucleotide/nucleoside molecules with different polarities and selectivities were successfully isolated in our laboratory using stainless-steel columns filled with the synthesized material. In addition, the separation of saccharide probes and oligosaccharides mixtures in water extracts of Morinda officinalis were compared in HILIC mode. The results showed that the resolution of separations for the representative analytes of the Sil-epoxy-PEI column was higher than for the Sil-chloropropyl-PEI column, and the developed stationary phase exhibited improved performance compared to hydrothermal carbon, amide columns and other HILIC materials previously reported.
研究领域:
分析化学
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天然产物研究
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药物化学
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ANALYTICA CHIMICA ACTA
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2015
·
IF 4.513
Wanshu Qi,Qing Guan,Tuanqi Sun,Yanjing Cao,Li Zhang,Yinlong Guo
In this work, 0.08 mmol L −1 of phthalic acid was introduced as a mobile phase additive to quantify free amino acids (AAs) by hydrophilic interaction liquid chromatography (HILIC) coupled with electrospray ionization tandem mass spectrometry (ESI-MS/MS). The addition of phthalic acid significantly increased the signal intensity of protonated AA ions, resulting from the decrease of the relative abundance of AA sodium adducts. Meanwhile, the chromatographic peak shapes of AAs were optimized. As a consequence, there was a noticeable increase in the sensitivity of detection for AAs. The limits of detection (LOD) and quantification (LOQ) of the AAs ranged from 0.0500 to 20.0 ng mL −1 and from 0.100 to 50.0 ng mL −1 , respectively, which were 4–50 times lower compared to the values measured without the addition of phthalic acid. The enhanced detection and separation of AAs were obtained by merely adding phthalic acid to the mobile phase without changing other conditions. Eventually, this simple method was validated and successfully applied to the analysis of twenty-four kinds of free AAs in human thyroid carcinoma and para-carcinoma tissues, demonstrating a significant increase of most AAs in thyroid carcinoma tissues ( p < 0.05).
研究领域:
分析化学
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医学
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PubMed
高影响因子
ANALYTICAL SCIENCES
·
2018
·Vol. 34
·期 4
·433-438
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IF 1.355
Li Hengye,Zhang Xuemeng,Zhang Lin,Cang Hui,Kong Fenying,Fan Dahe,Wang Wei
Surface-initiated anionic-ring-opening multibranching polymerization was employed to prepare a hyperbranched polyglycerol (HPG) functionalized silica stationary phase for hydrophilic interaction liquid chromatography (HILIC). The obtained stationary phase was characterized by Fourier-transform infrared spectrometry (FT-IR) and thermogravimetric analysis (TGA). The chromatographic properties of the prepared stationary phase were systematically investigated. The abundance and multitude distribution of hydroxyl groups in HPG endowed the stationary phase with improved hydrophilicity and enhanced separation performance compared with the stationary phase functionalized with monolayer of hydroxyl groups. The stationary phase showed excellent retention of various polar compounds, such as nucleosides, necleobases, phenols and sulfanilamides, indicating great potential in the separation of complex biosamples.
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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PubMed
高影响因子
ANALYST
·
2020
·Vol. 145
·期 11
·3851-3856
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IF 3.978
Tiantian Si,Licheng Wang,Xiaofeng Lu,Xiaojing Liang,Shuai Wang,Yong Guo
A new type of core–shell composite material was prepared and applied as a hydrophilic interaction liquid chromatography (HILIC) stationary phase. In this work, silica spheres were first modified with a bimetallic central metal–organic framework (ZnCoMOF) by a new strategy of static self-assembled in situ growth. This strategy was beneficial for increasing the electrostatic interaction between the MOF ligand and silica via introducing a sodium dodecylbenzenesulfonate (SDBS) group. The ZnCoMOF@silica stationary phase was characterized and evaluated in comparison with amino-modified and bare silica columns in terms of various polar analytes including eight nucleosides and nucleobases, seven carbohydrates, and multiple sulfonamides and antibiotics. The effects of organic solvent concentration, water content, the concentration of the salt and the pH of the buffer solution on the retention time were studied, which demonstrated the typical retention behavior of HILIC on the ZnCoMOF@silica column. Compared with most reported MOF-based stationary phases, the new composite material showed excellent hydrophilic properties and separation efficiency for various polar analytes. Moreover, the obtained stationary phase showed good reproducibility and stability. The relative standard deviation (RSD) of the retention time for repeatability was found to range from 0.1% to 0.6%, and the RSD of the retention time for stability was found to range from 0.3% to 0.7%. Furthermore, the column batch-to-batch reproducibility showed excellent preparation reproducibility, which few reported in most previous MOF@silica composite materials. This specific preparation method offers an easy and novel way to manipulate the amount of MOF particles on silica, which extends a universal way to produce various MOF@silica stationary phases by the method of static self-assembled in situ growth.
研究领域:
分析化学
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材料科学
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PubMed
高影响因子
JOURNAL OF FOOD COMPOSITION AND ANALYSIS
·
2024
·
IF 4
Jian-Jun Zhong,Lingling Zhao,Yuanxin Guo,Zhanming Li,Hua Ye,Huanan Guan,Zhiqiang Xing,Weiqing Wang
The coffee phytochemical trigonelline and its roasting products nicotinic acid and N -methylpyridinium represent an important class of bioactives that mediate the health benefits of coffee consumption. However, there is a paucity of methods for their simultaneous analysis in coffee beans, especially those affordable and reliable for widespread routine use. To improve this situation, an easy-to-use HPLC−UV method was developed in this study based on a reversed-phase/cation-exchange mixed-mode column showing unique chromatographic selectivity toward the polar and ionic analytes over the matrix components of coffee. The selectivity was achieved by using a decreasing acetonitrile gradient, which tuned the column to a cation-exchange/hydrophilic interaction (CEX/HILIC) mixed separation mode whilst minimizing its hydrophobic interaction capability. The method was assessed for figures of merit, giving limits of detection in coffee beans at around the 0.1 mg/100 g wet matter level, and verified for its applicability to a heterogeneous set of coffee bean samples differing in roasting degree and origin.
研究领域:
分析化学
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食品科学
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植物化学
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高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2016
·
IF 3.926
Haibin Li,Chusheng Liu,Qiqin Wang,Haibo Zhou,Zhengjin Jiang
In order to investigate the effect of charged groups present in hydrophilic monolithic stationary phases on their chromatographic properties, three charged hydrophilic monomers, i.e. N,N -dimethyl- N -acryloyloxyethyl- N -(3-sulfopropyl)ammonium betaine (SPDA), [2-(acryloyloxy)ethyl]trimethylammonium chloride (AETA), and 3-sulfopropyl acrylate potassium salt (SPA) were co-polymerized with the crosslinker N,N '-methylenebisacrylamide (MBA), respectively. The physicochemical properties of the three resulting charged hydrophilic monolithic columns were evaluated using scanning electron microscopy, ζ-potential analysis and micro-HPLC. High column efficiency was obtained on the three monolithic columns at a linear velocity of 1 mm/s using thiourea as test compound. Comparative characterization of the three charged HILIC phases was then carried out using a set of model compounds, including nucleobases, nucleosides, benzoic acid derivatives, phenols, β-blockers and small peptides. Depending on the combination of stationary phase/mobile phase/solute, both hydrophilic interaction and other potential secondary interactions, including electrostatic interaction, hydrogen-bonding interaction, molecular shape selectivity, could contribute to the over-all retention of the analytes. Because of the strong electrostatic interaction provided by the quaternary ammonium groups in the poly (AETA- co -MBA) monolith, this cationic HILIC monolith exhibited the strongest retention for benzoic acid derivatives and small peptides with distorted peak shapes and the weakest retention for basic β-blockers. The sulfonyl groups on the poly (SPA- co -MBA) hydrophilic monolith could provide strong electrostatic attraction and hydrogen bonding for positively charged analytes and hydrogen-donor/acceptor containing analytes, respectively. Therefore, basic drugs, nucleobases and nucleotides exhibited the strongest retention on this anionic monolith. Because of the weak but distinct cation exchange properties of the zwitterionic poly (SPDA- co -MBA) hydrophilic monolith, it exhibited the best separation for most test analytes (including phenols, β-blockers and small peptides) in terms of selectivity, peak shape and analysis time. The poly (AETA- co -MBA) hydrophilic monolithic column provides the best separation of nucleobases and nucleosides. These results could guide the selection and application of these charged HILIC monoliths in the future.
研究领域:
分析化学
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色谱技术
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PubMed
高影响因子
Journal of Analysis and Testing
·
2025
·
IF 7
Li Han,Cui Yuanyuan,Zhen Changqing,Lin Xiaohui,Li Ke,Yang Chengxiong
Microporous organic network (MON) has emerged as efficient stationary phases for high-performance liquid chromatographic (HPLC) separation. Nevertheless, the inherent superhydrophobic networks made their applications limited in the reversed-phase (RP) mode. In this work, a novel amino acid L-cysteine (L-Cys) modified core-shelled microsphere MON@SiO 2 -L-Cys was synthesized via the efficient thiol-yne “click” reaction for hydrophilic interaction chromatography /reversed-phase liquid chromatography (HILIC/RPLC) mixed-mode chromatographic separation. Baseline separation of various hydrophilic and hydrophobic compounds including aromatic ketones, phthalate esters, alkylbenzenes, amines, polycyclic aromatic hydrocarbons, phenols, nucleosides, nucleic acid bases, sulfonamides, water-soluble vitamins, cephalosporin antibiotics, and estrogens was realized on MON@SiO 2 -L-Cys packed column based on the predesigned mixed-mode retention mechanisms. The MON@SiO 2 -L-Cys packed column also exhibited higher selectivity compared to bare SiO 2 , MON@SiO 2 without L-Cys, and C 18 packed columns, revealing the synergistic interactions of MON’s networks and the modified L-Cys molecules. This work provided a feasible way to construct a novel amphipathic MON-based stationary phase, broadened the application scope of MON for hydrophilic analytes, and uncovered the prospects of MON in mixed-mode HPLC.
研究领域:
分析化学
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材料科学
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高影响因子
ANALYTICAL SCIENCES
·
2023
·
IF 1.6
Lai Liang,Zhang Mengyun,Liu Chusheng,Qu Jiahuan,Xu Dongsheng,Jiang Zhengjin
Rapid and effective separation of nucleotides (NTs) and their derivatives is crucial for studying their physiological functions. In this work, we comprehensively evaluated the separation ability of a zwitterionic hydrophilic monolith, i.e., poly(N,N-dimethyl-N-(3-methacrylamidopropyl)-N-(3-sulfopropyl)ammonium betaine- co –N,N’-methylenebisacrylamide) (poly(SPP- co -MBA)) for NTs analysis, including its selectivity, chemical stability under extremely basic condition and compatibility with hydrophilic interaction liquid chromatography (HILIC) coupled with mass spectrometry (HILIC-MS). The poly(SPP- co -MBA) monolith exhibited excellent chemical stability, as evidenced by the low relative standard deviation of retention time (0.16–1.05%) after 4000 consecutive injections over one month under strong alkaline elution condition (pH 10). After optimizing the separation conditions, including buffer pH and concentration, organic solvent content and column temperature, four nucleoside triphosphates, five nucleoside diphosphates and five nucleoside monophosphates were baseline separated within 7 min. Additionally, the mixtures containing one nucleoside and its corresponding mono-, di-, and triphosphates were baseline separated within only 3 min, respectively. It is good HILIC-MS compatibility was also confirmed by the satisfactory peak shape and high response of nine NTs. Overall, the proposed poly(SPP- co -MBA) monolith exhibited good mechanical stability and compatibility of HILIC-MS, making it a promising technique for NTs analysis. Graphical Abstract
研究领域:
分析化学
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生物化学
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PubMed
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CARBOHYDRATE POLYMERS
·
2024
·
IF 10.7
Yao-Yao Zhang,Si-Yu Zhang,Zi-Xuan Hu,Josef Voglmeir,Li Liu,M. Carmen Galan,Mattia Ghirardello
N -linked glycosylation is a ubiquitous protein post-translational modification in which aberrant glycan biosynthesis has been linked to severe conditions like cancer. Accurate qualitative and quantitative analysis of N -glycans are crucial for investigating their physiological functions. Owing to the intrinsic absence of chromophores and high polarity of the glycans, current detection methods are restricted to liquid chromatography and mass spectrometry. Herein, we describe three new imidazolium-based glycan tags: 2’GITag, 3’GITag, and 4’GITag, that significantly improve both the limit of detection and limit of quantification of derivatized oligosaccharides, in terms of fluorescence intensity and ionisation efficiency. Our top-performing derivatisation agent, 4’GITag, shifted the detection sensitivity range from high femtomole to sub-femtomole levels in ESI-MS compared to traditional glycan label, 2AB, enabling the identification of 24 N -glycans in mouse serum, including those bearing sialic acids. Additionally, 4’GITag stabilized Na-salt forms of sialic acids, simplifying the simultaneous analysis of neutral and negative charged N -glycans significantly, avoiding the need for complex derivatisation procedures typically required for the detection of sialylated species. Overall, the favorable performance of imidazolium tags in the derivatisation and sensitive profiling of glycans has the potential for labeling tissue or live cells to explore disease biomarkers and for developing new targeted therapeutic strategies.
研究领域:
生物化学
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分析化学
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生物医学工程
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分子生物学
·
癌症研究
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PubMed
高影响因子
危险品化学品经营许可证（带存储）