杯芳烃在液相色谱固定相领域的应用及进展

杯芳烃是一类由苯酚单元通过亚甲基桥连的超分子化合物,具有独特的主客体识别性能,是继冠醚和环糊精之后第三代超分子化合物的主要代表。其被广泛应用于离子通道、有机催化反应、跨膜转运、纯化、色谱分离等方面。基于杯芳烃易于修饰的特点,选取不同性质的化合物进行衍生化,可以制备出具有不同识别能力和高选择性的杯芳烃衍生物,进而应用于不同色谱分离模式,可实现复杂样品的分离分析。该文从杯芳烃、杯芳烃衍生物和杯杂芳烃3个方面综述了近年来杯芳烃在液相色谱固定相方面的研究应用及进展,并对杯芳烃在色谱分离领域的发展提出了展望。     

杯芳烃应用研究的新进展

杯芳烃是既能与离子型又能与非离子型客体形成配合物的新型大环配体，本文综述了近年来这类新型配体在铀和铯的提取，镧系元素和金属离子选择性萃取，中性有机分子的分离。水污染控制，相转移催化剂，酶模型催经反应，Ｌ－Ｂ膜，离子选择电极和场效应晶体管，有机材料的稳定剂，粘合剂的固化加速等领域中应用研究的最新进展，展望了其广阔的工业应用前景。     

对-叔丁基杯[8]芳烃键合固定相的制备及表征

合成了一种新的对-叔丁基杯[8]芳烃的高效液相色谱键合固定相,考察了多环芳烃、苯甲酸酯、邻苯二甲酸酯、苯的单官能团取代物在该键合相上的反相液相色谱保留行为,并以甲醇-水作为流动相分离了氨基苯酚的邻、间、对取代位置异构体．研究结果发现,该键合相具有明显的反相特征,并讨论了可能的分离机理．     

茂铁基二氢吡唑类衍生物的液相色谱分离研究

本文利用梯度洗脱进行溶剂强度的优化,确定分离一组化合物的最佳二元流动相体系,即甲醇-水、四氢呋喃-水和乙腈-水,将这三种二元流动相的最佳组成作为溶剂选择性三角形的三个顶点,利用ORM法对流动相进行优化选择,得到流动相的最佳组成和配比为V乙腈:V四氢呋喃:V水=33.75:33:33.25,有效地分离了六种二茂铁取代二氢...     

液晶和杯环芳烃混合固定相的协同效应研究

在以液晶和杯环芳烃为混合固定相分离苯／环己烷／正己烷,卤化烃,酮,芳烃,醇和胺的气相色谱中,发现存在混合固定相的协同效应,并且这种效应受一定的温度的影响。     

通过杯芳烃片段桥联合成杯[4]冠4齐聚物及其络合性能研究

通过杯芳烃片段桥联合成杯[4]冠4齐聚物,并通过两相萃取实验评估其络合性能。络合研究表明,酰胺型杯[4]冠4齐聚物（TCA[4]-III）对软金属银、铅离子和氨基酸具有选择性络合。其对色氨酸和组氨酸的萃取率分别高达87.9% 和 91.5%。     

多糖衍生物手性固定相上采用酸性或碱性添加剂的流动相拆分β受体阻滞剂对映体

考察了多糖类手性固定相在含有酸性或碱性添加剂的流动相下高效液相色谱法拆分β受体阻滞剂对映体的效果。色谱条件: 流动相为10%～30%(体积分数,下同)乙醇-正己烷(含0.1%三氟乙酸)和10%～30%乙醇-正己烷(含0.1%三乙胺),流速1.0 mL/min,紫外检测波长254 nm。结果表明,在直链淀粉-三(3,5-二甲基苯基氨基甲酸酯)衍生物手性固定相(Chiralpak AD和Chiralpak IA)上拆分β受体阻滞剂对映体,酸性添加剂的流动相体系与碱性添加剂的流动相体系相比,碱性添加剂的流动相的拆分效果比酸性添加剂的流动相要好。而在纤维素-三(3,5-二甲基苯基氨基甲酸酯)衍生物的手性固定相(Chiralcel OD和Chiralpak IB)上分离β受体阻滞剂,比较酸性添加剂的流动相与碱性添加剂的流动相的拆分效果,发现酸性添加剂的流动相条件下对映体的保留减弱,但对映体的选择性增大,特别是在Chiralcel OD上,酸性添加剂的流动相体系对对映体的选择性非常理想,而且随着流动相中酸性添加剂含量的增加,β受体阻滞剂对映体的分离效果更佳。     

对-叔丁基杯[4]芳烃键合固定相的制备及表征

合成了对一叔丁基杯[4]芳烃高效液相色谱键合固定相，分离了多环芳烃、硝基苯胺位置异构体、苯甲酸酯、邻苯二甲酸酯和苯的单官能团化合物；比较了在不同的流动相中分析物的保留行为，发现该键合相具有明显的反相特征，对位置异构体的分离优于C18柱，并讨论了可能的分离机理。     

大黄蒽醌衍生物在杯[8]芳烃键合固定相上色谱行为的研究

研究了药用掌叶大黄中5种蒽醌衍生物在对-叔丁基杯[8]芳烃硅胶键合固定相上的高效液相色谱行为,并与ODS固定相进行了比较。研究发现这类化合物与杯[8]芳烃固定相之间存在多种相互作用,除疏水作用外,分离过程中还存在与ODS不同的色谱分离机制。杯芳烃键合相与溶质之间的氢键作用、包容络合作用改变了杯芳烃固定相对它们的选择性。     

水溶性β-内酰胺对映体在β-环糊精键合固定相上的手性分离

本文介绍在β-环糊精键合固定相上水溶性单环β-内酰胺类化合物对映体的手性分离,考查了流动相组成和色谱柱温度对容量因子k′,对映体选择性α和峰分离度P的影响,比较了具有不同取代基的β-内酰胺样品的对映体的分离。     

大黄酸键合硅胶固定相的简便制备及色谱性能评价

以大黄酸为原料,γ-氨丙基三乙氧基硅烷(KH-550)为偶联剂,简便制备了一种新型羧基键合硅胶固定相(RBSP),并用红外光谱、热重分析及元素分析对其结构进行表征.考察了流动相中甲醇含量对键合固定相色谱性能的影响,并以含酸性、中性和碱性化合物的混合物为溶质,评价了RBSP的色谱性能.以甲醇-水为流动相,用C18柱作参比,研究了该键合硅胶作为HPLC固定相对两种大豆异黄酮化合物和几种生物碱基的分离,并对其色谱分离机理进行了初步探讨.实验结果表明,该固定相(RBSP)具有较好的反相色谱性能,同时由于键合相中含有酚羟基及酰胺基团,能为多种溶质提供作用位点,对极性化合物的分离具有明显优势,且分离速度快,可有效用于极性化合物的分离分析.     

Retention of C60 and C70 fullerenes on reversed-phase high-performance liquid chromatographic stationary phases.

The separation of C60 and C70 fullerenes on four different polysiloxane stationary phases was examined. It was determined that polar solvents can be used as mobile phases effectively for the separation of fullerene molecules. Unlike previously published work, a polymeric octadecyl siloxane (ODS) stationary phase provided higher separation factors for C70/C60 than did monomeric ODS stationary phases or phenyl substituted stationary phases. For example, for a methanol-diethyl ether (50:50, v/v) mobile phase and C60, k' approximately 5.0 separation factors, alpha = 3.3, were achieved with polymeric ODS compared to alpha = 2.2, with a monomeric ODS stationary phase. A linear solvation energy relationship (LSER) was used to model the importance of solvent interactions and stationary phase interaction to solute retention.     

氮杂冠醚键合固定相的RP-HPLC色谱性能研究

报道在硅胶表面进行固-液相反应合成的3-(氮杂-18-冠-6)丙基键合固定相对金属离子的络合能力和色谱性能,研究了流动相组成、pH值、金属离子对极性二取代苯保留值的影响,探讨色谱分离机理。这种键合相通过对金属离子的络合,显示多种色谱分离机理,对极性二取代苯异构体分离选择性、分析速度均优于对比的C₁₈键合固定相反相色谱。     

姜黄素键合硅胶固定相的制备、表征及色谱性能

通过γ-［(2,3)-环氧丙氧］丙基三甲氧基硅烷(KH-560)偶联剂将具有抗菌功能的植物有效成分姜黄素键合到硅胶上,制备了姜黄素液相色谱键合硅胶固定相(CCSP)。采用元素分析、红外光谱和热分析对该固定相结构进行了表征。以甲醇和水为二元流动相,不同的中性、酸性和碱性化合物为溶质探针,并用ODS柱作参比,对固定相的色谱性能及保留机理进行了研究。研究结果表明,姜黄素键合固定相不仅具有良好的反相色谱性能,同时由于配体结构中所含有的基团形成了含芳环的共轭体系,从而引入了n-π和π-π作用位点,所含的羟基和β-二羰基与溶质之间存在偶极-偶极和氢键作用,与ODS相比,该固定相在极性化合物分离中占优势,且分析速度较快。     

高效液相色谱槲皮素键合硅胶固定相分离极性化合物

槲皮素是一种植物体中含量丰富、价格较便宜的黄酮类化合物,本研究以γ-[(2,3)-环氧丙氧]丙基三甲氧基硅烷(KH-560)为偶联剂,将其化学键合到硅胶上,得到一种含天然配体的槲皮素键合硅胶固定相(QUSP)。 采用红外光谱、热重分析、元素分析及固体核磁对其结构进行表征,测得硅胶表面槲皮素的键合量为0.139 mmol/g。 采用不同结构的溶质作探针,在评价固定相反相液相色谱疏水作用性能的基础上,侧重研究新固定相对极性芳香族化合物的分离能力,探讨了新固定相的色谱分离机理。 研究表明,仅采用甲醇或乙腈-水简单流动相,无需用缓冲液精确控制pH值,QUSP就能分别实现吡啶类、芳胺类、苯酚类、苯甲酸类和黄酮类等极性化合物的快速基线分离。 QUSP键合的槲皮素除含疏水性的C6-C3-C6骨架外,黄酮环还能为溶质提供氢键、偶极、π-π、电荷转移等多种作用位点,各种协同作用有利于提高色谱分离选择性,尤其对极性的可离子化的酸性和碱性化合物。     

A Study of Polynuclear Aromatic Hydrocarbons on an Amino Bonded Phase Liquid Chromatographic Column in the Normal and Reversed Phase

Abstract

Experiments were run using an n-propyl amine polar bonded phase (Chromosorb LC-9) liquid chromatographic column in both the normal and reversed phase mode. Results confirm that the mechanism of separation in the normal phase is due mainly to a charge transfer interaction between the lone pair electrons on the stationary phase nitrogen and the π electron cloud of the solute PNAs. Elution order seems to depend upon a combination of π energy, and type of ring condensation of the solute. Plots of log I versus number of aromatic carbons for catacondensed PNAs suggest that while the specific interaction is different than that seen in silica chromatography, the overall adsorption effect is comparable. In the reversed phase there may be two types of separation mechanisms: 1) a pure partitioning effect in highly polar mobile phases (methanol/water), or 2) a mixture of liquid-solid adsorption and liquid-liquid partition in less polar solvent systems (acetonitrile/water).     

Stationary and mobile phases in hydrophilic interaction chromatography: a review

Hydrophilic interaction chromatography (HILIC) is valuable alternative to reversed-phase liquid chromatography separations of polar, weakly acidic or basic samples. In principle, this separation mode can be characterized as normal-phase chromatography on polar columns in aqueous-organic mobile phases rich in organic solvents (usually acetonitrile). Highly organic HILIC mobile phases usually enhance ionization in the electrospray ion source of a mass spectrometer, in comparison to mobile phases with higher concentrations of water generally used in reversed-phase (RP) LC separations of polar or ionic compounds, which is another reason for increasing popularity of this technique. Various columns can be used in the HILIC mode for separations of peptides, proteins, oligosaccharides, drugs, metabolites and various natural compounds: bare silica gel, silica-based amino-, amido-, cyano-, carbamate-, diol-, polyol-, zwitterionic sulfobetaine, or poly(2-sulphoethyl aspartamide) and other polar stationary phases chemically bonded on silica gel support, but also ion exchangers or zwitterionic materials showing combined HILIC-ion interaction retention mechanism. Some stationary phases are designed to enhance the mixed-mode retention character. Many polar columns show some contributions of reversed phase (hydrophobic) separation mechanism, depending on the composition of the mobile phase, which can be tuned to suit specific separation problems. Because the separation selectivity in the HILIC mode is complementary to that in reversed-phase and other modes, combinations of the HILIC, RP and other systems are attractive for two-dimensional applications. This review deals with recent advances in the development of HILIC phase separation systems with special attention to the properties of stationary phases. The effects of the mobile phase, of sample structure and of temperature on separation are addressed, too.     

Study of solvation processes on cholesterol bonded phases

Four cholesterol bonded phases with different structures were investigated. The columns studied were packed with stationary phase containing cholesterol attached to the silica surface using different types of linkage molecules. The presence of the polar amino and carboxyl groups in the structure of the bonded ligand strongly influence on the solvation process. The possibility of hydrogen bonding, dipole-dipole and π-π electron interactions lead to preferential solvation of bonded ligands. The coverage density of bonded ligands and length of the linkage strongly influence the adsorption of solvent from the mobile phase. The removal of residual silanols during the hydrosilation procedure significantly influences solvation of the bonded phase. Excess isotherms of the commonly used solvents in RP HPLC (methanol and acetonitrile) were obtained using the minor disturbance method. For comparison of the stationary phases prepared on different silica gels the excess adsorbed amounts were calculated per volume of the stationary phase in the column. The hydrosilated UDC Cholesterol bonded phase is preferentially solvated by methanol whereas the highest coverage Cosmosil Cholester phase exhibit high adsorption of acetonitrile. Polar groups in the Amino-cholesterol type bonded phase are solvated with both solvent but the mechanisms of these processes are different.     

新型杯[4]芳烃高效液相色谱固定相的制备及表征

合成了一种新型的杯[4]芳烃高效液相色谱键合固定相，考察了它的反相色谱行为．通过对多环芳烃、二取代苯的位置异构体、苯甲酸酯和邻苯二甲酸酯的分离，发现该键合相具有显著的反相特征，对位置异构体具有很高的识别能力，其分离明显优于C18柱，并讨论了可能的分离机理．     

Selection of the Mobile Phase for Enantiomeric Resolution via Chiral Stationary Phase Columns

Abstract

The optimization of enantiomeric resolution by mobile phase variation was studied with the chiral stationary phase derived from R-N-(3,5-dinitrobenzoyl) phenylglycine covalently coupled to 5 μm spherical 3-aminopropyl silica. Chromatography was routinely performed with mobile phase compositions having polarities as high as 2.5 without column deterioration. The relative strength of a solvent as a hydrogen acceptor was found to be an important basis for selection of the polar component in a binary mobile phase. The substitution of tert-butanol for 2-propanol or ethanol in an alcohol/hexane mixture, for example, afforded improved separation factors with several enantiomers. In addition, the need for a polar mobile phase such as 50/50 methylene chloride/hexane to minimize non-specific polar absorption of enantiomers has been demonstrated. Enhancement of specific chiral interactions and suppression of interfering reactions have been obtained with a number of clinically relevant derivatives as model compounds.