Synthesis of Cellulose Tris (4-Methylbenzoate) as Gas Chromatographic Stationary Phase and its Characterization

The cellulose tris (4-methylbenzoate) has been synthesised by the catalytic method and was supported at Gas Chrom Q. The absorption capability of cellulose tris (4-methylbenzoate) used as a gas chromatographic stationary phase was characterized by chromatographic method and the Clausius-Clapeyron equation. However, n-alcohols (C-1-C-8) were successfully separated on the column packed with Gas Chrom Q coated with cellullose tris (4-methylbenzoate).

Liquid Chromatographic Resolution of Racemic 2-Phenyl-1,1-cyclopropanedicarbonitrile and its Analogues on Chiral Stationary Phase

Excellent resolution of racemic 2-phenyl-1,1-cyclopropanedicarbonitrile and its nine analogues was accomplished using 100-5CH1-TBB chiral stationary phase under normal-phase HPLC conditions. The influence of mobile phase and the optimum conditions for the resolution of optically active enantiomers were investigated.

An Excellent Gas Chromatographic Stationary Phase for Separation of Phenol and Cresol Isomers--Heptakis(2,6-di-O-pentyl-3-O-allyl)-β-Cyclodextrin

Heptakis(2.6-di-O-pentyl-3-O-ally)-β-cyclodextrin as an excellent gas chromatographic stationary phase separating phenol and cresol isomers is described.

Two-dimensional MOF Cu-BDC nanosheets/ILs@silica core-shell composites as mixed-mode stationary phase for high performance liquid chromatography

Here,silica microspheres were decorated with two-dimensional metal-organic frameworks(2 D MOFs)nanosheets and ionic liquids,and evaluated as the mixed-mode stationary phase for chromatographic separation.The ionic liquids were used to assist the synthesis of 2 D MOFs nanosheets,and also acted as adhesives among the nanosheets and silica.In contrast with the 2 D MOFs-based column without ionic liquids and commercial columns,the prepared column exhibited enhanced chromatographic separation performance for partially hydrophilic compounds such as alkaloids,sulfonamides and antibiotics,etc.In addition to excellent chromatographic repeatability and stability,it has also been verified that the composites could be easily and repeatedly prepared.The relative standard deviation of the retention time of the same type of analyte between the three batches of materials was ranging from 0.21%to 1.7%.In short,these results indicated that the synthesized composites were promising separation material for liquid chromatography,which made it possible to broaden the application of 2 D MOFs in the field of chromatography.

Reversed-phase fused-core HPLC modeling of peptides

Different fused-core stationary phase chemistries（C18,Amide,Phenyl-hexyl and Peptide ES-C18） were used for the analysis of 21 structurally representative model peptides.In addition,the effects of the mobile phase composition（ACN or MeOH as organic modifier;formic acid or acetic acid,as acidifying component） on the column selectivity,peak shape and overall chromatographic performance were evaluated.The RP-amide column,combined with a formic acid-acetonitrile based gradient system,performed as best.A peptide reversed-phase retention model is proposed,consisting of 5 variables：log SumAA,log Sv,clog P,log nHDon and log nHAcc.Quantitative structure-retention relationship（QSRR） models were constructed for 16 different chromatographic systems.The accuracy of this peptide retention model was demonstrated by the comparison between predicted and experimentally obtained retention times,explaining on average 86% of the variability.Moreover,using an external set of 5 validation peptides,the predictive power of the model was also demonstrated.This peptide retention model includes the novel in-silico calculated amino acid descriptor,AA,which was calculated from log P,3D-MoRSE,RDF and WHIM descriptors.

Exploiting styrene-maleic acid copolymer grafting chromatographic stationary phase materials for separation of membrane lipids

High performance liquid chromatography-mass spectrometry is one of the most commonly used strategies for lipid analysis.The development of versatile chromatographic stationary phases to meet the increasing demands for separation of complex lipids is very important.Styrene-maleic acid(SMA)copolymer is an amphiphilic polymer,which has been proven to have the ability to solubilize lipid molecules of various structures.In this study,styrene-maleic anhydride copolymer coated silica was first prepared by the thiol-ene click reaction.With L-cysteine hydrochloride or dodecanol as the post-modification reagents,Sil-SMA-amino acid and Sil-SMA-dodecanol stationary phase materials were further successfully fabricated via nucleophilic ring-opening reaction.The Fourier-transform infrared,thermogravimetric analysis,and elemental analysis results confirmed the two stationary phase materials were successfully prepared.Furthermore,both the Sil-SMA-dodecanol column and the Sil-SMA-amino acid column possessed reversed-phase/hydrophilic interaction/ion exchange mixed-mode retention mechanisms.The column efficiency of the Sil-SMA-derivatives columns reached 77,300 N/m.Based on the mixed-mode retention characteristics,the Sil-SMA-derivatives columns achieved both the lipid classes and species separation via a single column.The Sil-SMA-amino acid column was further successfully used to separate lipid extract from gastric cancer cell membrane.All these results demonstrated that the SMA-based stationary phase materials have a good potential for use in lipid separation.

纳米晶纤维素组装的手性介孔材料及其对手性药物的分离

纤维素纳米晶体(CNC)是由硫酸催化的纤维素水解制备的,根据纤维素的来源和水解条件,纳米晶体的直径约为5~15 nm,长度约为100~300 nm。CNC在水中可以形成具有手性向列型结构的液晶相。当干燥成固体薄膜时,CNC保持螺旋手性向列顺序并组装成层状结构。在CNC自组装过程中,可以添加溶胶-凝胶前体,如Si(OMe)_(4)。随着溶剂的蒸发,这些前体会发生水解和缩合,从而形成手性向列相二氧化硅/CNC复合材料。复合材料在空气中煅烧破坏纤维素模板,留下高表面积手性向列结构的介孔二氧化硅膜。此外,有机二氧化硅或二氧化钛薄膜也采用类似的方法得到。这些薄膜可用作滤光片、反射器和薄膜。最重要的是,合成的手性介孔二氧化硅可用作手性色谱固定相材料分离手性药物。结果显示,手性分离的效果显著,为CNC开发手性新材料提供了新方法。

用于分离单糖与寡糖的亲水色谱材料制备及应用进展

糖类化合物在食品科学、医药科学、生命科学等领域中发挥至关重要的作用。糖类化合物可分为单糖、寡糖和多糖,其中单糖和寡糖大多是可溶性糖,不仅可以充当结构物质,还具有抗氧化、抗癌、抗菌、抗病毒等多种生物活性。亲水作用色谱弥补了反相液相色谱在糖类化合物分离方面的不足。本文重点介绍了2017—2022年报道的适合分离分析单糖和寡糖的氨基键合固定相、酰胺类键合固定相、糖类键合固定相、两性离子键合固定相等亲水色谱固定相,并概述了乙腈含量、缓冲盐浓度、流动相pH值和柱温等色谱分离条件对亲水分离效果的影响,以期为单糖及寡糖的分离分析提供一定的参考。

基于二维材料的色谱固定相制备及应用

自2004年首次报道以来,二维材料因具有纳米级厚度、高比表面积、独特的层状结构和优异的机械性能等特点,受到了广泛关注。在导电、导热、气体存储和分离、膜分离以及催化等领域,二维材料均展现出了广阔的应用前景;其中,最为知名的二维材料是石墨烯,其是由单层碳原子构成的二维晶格结构,拥有较大的比表面积和优良的吸附性能,因而备受青睐。除此之外,二维材料还包括类石墨相氮化碳、氮化硼、过渡金属硫化物等。随着网状化学的不断发展,二维多孔框架材料逐渐受到关注,这类材料拥有纳米片状的形态、一维的孔道结构以及特殊的层间作用力,具有作用力丰富和可设计性强等优势,在色谱分离领域展现出了巨大的应用潜力。本文首先简要介绍了二维材料的合成方法与分离机理,随后着重介绍了近年来二维多孔框架材料在气相色谱及液相色谱固定相应用方面的最新研究进展。同时,本文也涉及了一些其他二维材料在色谱领域的应用,并对二维材料在色谱分离领域的发展前景进行了展望,期望为基于二维材料的色谱分离材料设计及应用提供参考。

Chiral metal-organic frameworks-based materials for chromatographic enantioseparation

The homochiral compounds play an important role in human health and pharmaceutical industry.Currently,the chromatographic enantioseparation has become one of the most effective and practical approach to obtain pure enantiomers.Herein,the exploration of advanced materials,using as chromatographic chiral stationary phases for racemic separation,has attracted great attention.Thanks to their high enantioselectivity and controllable synthesis,the emerging chiral metal-organic frameworks (CMOFs)have been widely studied as the stationary phase in chromatographic technology.In this review,we will summarize the principles of synthetic strategies and mechanism of chiral microenvironment.In particular,the recent progress and research hotspot of CMOFs regarding as the chiral stationary phases in gas chromatography (GC),high-performance liquid chromatography (HPLC),and capillary electrochromatography (CEC),are elucidated systematically according to the published work.Last but not the least,we also highlight the challenges and perspectives of rational design of CMOFs,as well as their corresponding racemic separation.We envision that the review will provide a further understanding of CMOFs and facilitate the development of chromatographic enantioselective applications.

Preparation and Characterization of a New Quercetin-bonded Stationary Phase for High Performance Liquid Chromatography

A quercetin-bonded silica gel stationary phase （QUSP） containing natural flavonoid ligand was first prepared via γ-glycidoxypropyltrimethoxysilane （KH-560） as a coupling reagent for high-performance liquid chromatography. Its chemical structure was characterized by Fourier infrared spectroscopy, elemental analysis, thermal thermogravimetry and 13C cross polarization/magic angle spinning nuclear magnetic resonance （CP/MAS NMR）. The chromatographic property of QUSP was systematically evaluated by using neutral, basic and acidic aromatic com- pounds as probes. In order to clarify its retention mechanism, a comparative study of QUSP with conventional oc- tadecylsilyl-bonded stationary phase （ODS） was also carried out under the same conditions. The results showed that the new quercetin-bonded phase exhibited an excellent reversed-phase chromatographic property with relatively weak hydrophobicity. However, it has an advantage over ODS in the fast separation of polar aromatic compounds because the quercetin ligand could provide various sites besides hydrophobicity, such as hydrogen bonding, dipole-dipole, n-n staking and charge transfer interactions. QUSP was performed in the baseline separations of ion- ized polar basic or acidic compounds, including pyridines, anilines, pyrimidines, purines and phenols with symmet- ric peak shape in common mobile phases without buffer salt within relatively short time. The natural ligands from herbs are readily available and contain a variety of active sites, which facilitate the exploration of industrial chromatographic separation materials for green products.

Preparation and Evaluation of Silicon Quantum Dots-Bonded Silica Stationary Phase for Reversed-Phase Chromatography

In this paper,silicon quantum dots(SiQDs)with green fluorescence are synthesized by solvothermal reaction of 3-(2,3-epoxypropoxy)propyltrimethoxysilane(GPTMS)and ethylenediaminetetraacetic acid(EDTA),and then SiQDs are bonded to the surface of silica to obtain a new nano-on-micro stationary phase(SiO_(2)-SiQDs)for reversed-phase chromatography.The successful preparation of SiO_(2)-SiQDs stationary phase is demonstrated by a variety of characterizations,such as transmission electron microscopy,laser confocal microscopy,elemental analysis and Fourier infrared spectroscopy.In addition,the chromatographic performance of the prepared stationary phase is evaluated and it shows good separation performance for non-polar substances such as alkylbenzene,aniline and polycyclic aromatic hydrocarbons in reversed-phase liquid chromatography.It is also verified that the stationary phase has good methyl selectivity and shape selectivity.More interestingly,the separation of prednisolone and hydrocortisone isomers can also be achieved at a low ratio of organic solvents,indicating that this new stationary phase has a good application prospect in isomer separation.

本科生综合实验:基于共价有机框架的核壳型固定相的制备及色谱性能评价

在教育部不断推进新课程标准的背景下,本文介绍了一项面向本科生仪器分析课程的综合性教学实验,旨在通过实践提高学生在材料制备和仪器使用方面的技能。该实验通过“一锅法”制备了一种基于共价有机框架的核壳结构固定相材料(SiO_(2)@COF_(TTA-DHTA)),并对其进行了详细的理化表征。随后,采用高效液相色谱技术对该材料的色谱性能进行了评估。整个实验流程包括了材料合成、表征、色谱保留行为研究和色谱分离性能测试。该实验不仅加深了学生对于功能材料性质及其应用的理解,而且提高了他们的实验设计和批判性思维能力。通过理论科学与实验教学的结合,该实验不仅能够培养学生的科研兴趣,还可以锻炼实验操作能力、创新思维和实践能力,同时增强学生的社会责任感和历史使命感,实现实验教学的全方位育人目标。

气相色谱毛细管柱的选择

气相色谱已成为石油化工中重要的分析方法,在研究挥发性与半挥发性成分时发挥着重要的作用,对于常规的应用和研究都具有重要的意义。而气相色谱柱是气相色谱的核心。选择合适的色谱柱可以改善色谱分离结果,快速提高实验效率。本文从固定相、柱内径、膜厚、柱长与相位比(β)等多个角度描述色谱分离的基本原理,介绍选择毛细管色谱柱的相关概念,供相关实验人员参考。

柠檬酸色谱分离过程的吸附性质研究

提出了一种通过在分析型柱上测定和模拟不同温度时的柱床空隙率和吸附等温线等热力学性能的变化行为 ,来筛选和研究用于从发酵液中以色谱法分离提纯柠檬酸的固定相结构的方法。

新型季磷离子液体气相色谱柱的制备及应用

选择季磷型离子液体为气相色谱固定相,采用静态法将其涂渍于纳米级SiO2预处理的毛细管内壁上制备成毛细管气相色谱柱。考察了此固定相的基本色谱性能和极性,并详细研究了其对多种化合物的分离性能和保留特点。研究表明,此该离子液体色谱柱的柱效为1381plates/m,极性为559.6,与商品化的聚乙二醇(PEG20M)和硝基对苯二甲酸改性的聚乙二醇(FFAP)柱的极性相近。此固定相对给质子体化合物的保留作用明显强于PEG20M,并且其对芳香化合物的间位和对位异构体的分离选择性明显优于自制的PEG20M。此固定相对芳香位置异构体、烷烃、多环芳烃、氯苯、醇类等均具有较好的分离效果。

新型离子液体气相色谱固定相研究

合成了一种用作新型气相色谱固定相的室温离子液体[C7H17NO]+[(CF3SO2)2N]-,并考察其色谱性能。该固定相具有较好的成膜性、较高的柱效、较强的极性,对正构烷烃、芳香族化合物以及一些位置异构体具有良好的分离效果。

亲水作用色谱固定相及其在中药分离中的应用

亲水作用色谱(HILIC)作为一种分离极性化合物的液相色谱模式,近年来越来越受到关注和重视。一方面是因为强极性化合物的分离问题引起了各个研究领域的重视,如药物分析、代谢组学、蛋白质组学等研究领域都不同程度地涉及强极性化合物的分离问题;另一方面是由于HILIC具有流动相组成简单、分离效率较高、与质谱兼容以及反压较低等优势。固定相是HILIC发展和应用的基础,本文主要从固定相分子结构的角度对HILIC固定相的结构特征、保留特性以及应用概况等进行了综述。对传统正相色谱固定相用于HILIC以及专门设计的HILIC固定相进行了介绍,评述了各自的优缺点和应用概况;对近年来HILIC固定相在中药分离中的应用进行了介绍;并对HILIC固定相的发展进行了展望。

分子印迹技术在分析检测领域的应用

分子印迹,属于超分子化学研究的范畴,是指以目标分子为模板,制备对该分子有特异选择性识别的聚合物的过程。分子印迹聚合物以其结构预定性、特异识别性和实用性的特点,引起了全世界范围的关注。因其具有与天然抗体同样的识别性能和与高分子同样的抗腐蚀性能的双重优点,因而广泛应用于生物工程、临床医学、环境监测、食品工业等众多领域。本文综述了分子印迹技术的发展历程,分子印迹聚合物的制备原理及方法以及在固相萃取、色谱分离、膜分离以及传感器领域的应用。色谱分离领域中对分子印迹在高效液相色谱、薄层色谱和毛细管电泳,以及传感器领域中分别对分子印迹光学传感器和电化学传感器的应用现状进行了阐述,最后对该技术进行了展望。

新型碳纳米管色谱固定相制备的研究进展

碳纳米管(CNTs)作为一种新型的功能材料,具有优异的物理、化学和机械性能,已经在分析化学领域得到了广泛的关注和应用。通过填充法或原位化学气相沉积法,可制备CNTs气相色谱固定相;将CNTs沉积在硅胶微球或有机聚合物基质微球表面,可制备填充式CNTs液相色谱固定相;通过包埋共聚法将CNTs嵌入聚合物整体柱内,可制备毛细管CNTs液相色谱整体柱。本文主要综述了近年来CNTs(单壁碳纳米管和多壁碳纳米管)用于色谱固定相制备的研究现状,包括气相色谱及液相色谱,并对该领域今后的发展进行展望。