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1.
将硅烷偶联剂γ-(2,3-环氧丙氧)丙基三甲氧基硅烷(KH560)先与十八醇反应,再键合到硅胶整体柱上,得到醚型十八烷基键合硅胶整体柱,并用红外光谱对其进行了表征.利用该固定相,在甲醇-水简单的二元流动相体系下,考察了该整体柱适用的pH范围,以及流速与柱压降和流速与柱效的关系,用该固定相对苯及其同系物进行了分离,并对尼群地平、硝苯地平和间尼索地平进行了分离.结果表明,该硅胶整体柱键合效果良好,具有较好的反相色谱性能,且在pH=2~8范围内稳定性好,柱压降、柱效受流速影响较小,可有效地用于化合物的快速分离分析. 相似文献
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以硅酸钾为硅源,甲酰胺为催化剂在毛细管内原位聚合形成干凝胶柱,制备了一系列致密度不同的整体柱。该法在柱制备及高温干燥过程中不会发生柱床断裂和塌陷现象,此特点明显优于以烷氧基硅烷为前驱体制备无机整体柱的方法。考察了不同模数硅酸钾对整体柱柱床结构的影响,用扫描电镜(SEM)和氮吸附法对整体柱结构进行了表征,考察了整体柱柱压与流速的关系;对整体柱进行十八烷基修饰后,测定了反相整体柱(C18整体柱)对蒽的柱效,通过考察甲苯在该柱上的突破曲线,获得了其对甲苯的柱容量。结果显示该整体柱柱床刚性好,在高温、高柱压、高流速时柱床能保持其物理结构的稳定性,对蒽的柱效达到41400理论塔板/m,对甲苯的柱容量为61 ng。 相似文献
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酯型十八烷基键合硅胶整体柱的制备、表征及性能评价 总被引:3,自引:0,他引:3
将硅烷偶联剂γ-(2,3-环氧丙氧)丙基三甲氧基硅烷与十八酸反应,再键合到硅胶整体柱上,得到了酯型十八烷基键合固定相,并用红外光谱、元素分析对其进行了表征。在以甲醇-水为流动相的反相色谱条件下分离了苯、联苯和蒽的混合样品,评价了该整体柱的色谱性能,考察了该整体柱适用的pH范围,以及柱压降、柱效与流速的关系。结果表明,该硅胶整体柱键合效果良好,具有较好的反相色谱性能,且在pH=2~8时稳定性好,柱压降、柱效受流速影响较小,可有效地用于化合物的快速分离分析。 相似文献
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乙烯基酯树脂整体柱用于溶菌酶的分离 总被引:1,自引:0,他引:1
以甲基丙烯酸间苯二酚二缩甘油酯树脂兼作单体和交联剂,偶氮二异丁腈(AIBN)为引发剂,十六醇为致孔剂,在不锈钢柱管中制成聚合物整体柱,通过电镜分析考察了该聚合物的微观孔结构.以此聚合物整体柱为基质,将该柱修饰为具有二醇基的聚合物整体柱,考察了此修饰柱的通透性,并将其作为高效液相色谱固定相考察了该柱对溶菌酶(Lys)的最大吸附量、α-淀粉酶(α-Amy)和溶菌酶在该柱上的分离,并对蛋清中的溶菌酶进行了分离.结果表明,分离效果良好,为蛋白分离提供了一种简单、快捷、有效的方法. 相似文献
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2,4-二氯苯氧乙酸分子印迹整体柱的制备、表征及色谱性能研究 总被引:8,自引:3,他引:5
以2,4-二氯苯氧乙酸分子为模板,甲基丙烯酸为单体,乙二醇二甲基丙烯酸酯为交联剂,甲苯和十二醇为混合致孔剂,采用热引发原位聚合法制备了作为高效液相色谱固定相的分子印迹整体柱.用红外光谱、扫描电镜、比表面积分析法对聚合物进行了表征.考察了模板分子在不同条件下合成的印迹整体柱及空白整体柱上容量因子的变化规律,同时探讨了流动相中甲醇的体积分数、pH值、流速对印迹整体柱分离性能的影响.结果表明,在优化的合成条件下制备的分子印迹整体柱可在15 min内分离2,4-二氯苯氧乙酸及其类似物苯氧乙酸,分离度为1.52.对柑桔提取液进行了分离测试,结果满意. 相似文献
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Hydrothermal preparation of hybrid carbon/silica monolithic capillary column for liquid chromatography 下载免费PDF全文
A simple, easy and economical approach for the preparation of a hybrid carbon/silica monolithic capillary column was described for the first time by using silica monolith as framework in combination with hydrothermal carbonization at 180°C. During the preparation process, formamide was introduced to the reaction solutions to reduce the dissolution rate of monolithic silica skeleton and its optimal concentration was 1.5 M. Fourier transform infrared spectrometry, scanning electron microscopy, energy dispersive X‐ray spectrometry, and inverse size exclusion chromatography were carried out to characterize the as‐prepared column. The results demonstrated that carbon spheres ranging from 150 to 1000 nm were successfully attached to the surface of silica skeleton. The prepared hybrid carbon/silica column had a permeability of 4.4 × 10?14 m2. Chromatographic performance of the column was evaluated by separation of various compounds including alkylbenzenes, nucleosides and bases, and aromatic acids. The column exhibited an efficiency of 75 000 plates/m for butylbenzene at the optimal linear velocity of 0.23 mm/s. The successful separation of these compounds and the study on mechanism indicated that the column can be applied in mixed‐mode chromatography. 相似文献
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We here report a new type of stationary phase for microcolumns. C18 modified silica monolith particles were prepared by grinding and sieving the silica monolith followed by C18 modification and end-capping, and were used as packing material. Ground silica monolith particles were not spherical but irregular with some residual monolithic network structure. The separation efficiency of the stationary phase made of sieved monolith particles (5-10 microm) was better than that of the stationary phase made of unsieved particles. The microcolumn packed with the sieved C18 ground monolith particles (5-10 microm) showed quite good separation efficiency (height equivalent to theoretical plate, HETP, as low as 15 microm) and it was even superior to the microcolumn packed with a commercial spherical 5 microm C18 stationary phase. The column pressure drop of C18 monolith particles was about two-third of that of the commercial spherical C18 phase. The preparation method of C18 stationary phase with ground and sieved silica monolith particles presumably suggests advantages of simplicity and convenience in modification and washing procedures compared to bulk silica monolith. It also showed both improved separation efficiency and low back pressure. 相似文献
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Deng Y Deng C Yang D Wang C Fu S Zhang X 《Chemical communications (Cambridge, England)》2005,(44):5548-5550
Magnetic silica nanoparticle functionalized multi-walled carbon nanotubes (MS-MWNTs) were prepared, characterized and used for the convenient, rapid and efficient separation of trace aromatic compounds. 相似文献
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Monolithic silica columns have inspired considerable research interests in the separation science because of their unique properties in permeability, mass transfer, efficiency and throughput. In this paper, a chemically p-tert-butylcalix[8]arene-bonded silica monolith was prepared as the promising candidate for versatile LC separations. Micrometer-sized macropores and nanometer-sized mesopores in this derivatized silica monolith reduce the diffusion path length and provide both low backpressure and high column efficiencies, leading to high-speed and high-throughput separations. Since p-tert-butylcalix[8]arene possesses a pi-donors cavity composed of benzene rings while polycyclic aromatic hydrocarbons, anthraquinones, phenol regio isomers and fullerenes are pi-systems with appreciable electron affinity, they may have a chance to get involved in forming host-guest inclusion complexes through non-covalent interactions, e.g. hydrophobic and pi-pi interactions. Compared with RP-18e, the prepared calixarene-bonded monolith exhibited better selectivity to molecules which contains more pi-electrons and more condensed cyclic moieties. The column efficiency was about 22,000 plates/m. The calixarene-bonded monolith also showed its good performances in separation of fullerenes and dihydropyridines, indicating a promising approach for purification of fullerenes with high purity from the carbon soot. 相似文献
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An affinity monolith based on silica and containing immobilized alpha(1)-acid glycoprotein (AGP) was developed and evaluated in terms of its binding, efficiency and selectivity in chiral separations. The results were compared with data obtained for the same protein when used as a chiral stationary phase with HPLC-grade silica particles or monoliths based on a copolymer of glycidyl methacrylate (GMA) and ethylene dimethacrylate (EDMA). The surface coverage of AGP in the silica monolith was 18% higher than that obtained with silica particles and 61% higher than that measured for a GMA/EDMA monolith. The higher surface area of the silica monolith gave materials that contained 1.5- to 3.6-times more immobilized protein per unit volume when compared to silica particles or a GMA/EDMA monolith. The retention, efficiency and resolving power of the AGP silica monolith were evaluated by injecting two chiral analytes onto this column (i.e., R/S-warfarin and R/S-propranolol). In each case, the AGP silica monolith gave higher retention plus better resolution and efficiency than AGP columns containing silica particles or a GMA/EDMA monolith. The AGP silica monolith also gave lower back pressures and separation impedances than these other materials. It was concluded that silica monoliths can be valuable alternatives to silica particles or GMA/EDMA monoliths when used with AGP as a chiral stationary phase. 相似文献
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Guihua Huang Wencan Zeng Xucong Lin Zenghong Xie 《Journal of separation science》2010,33(11):1625-1632
A porous zwitterionic monolith was prepared by in situ covalent attachment of lysine to a γ‐glycidoxypropyltrimethosysilane‐modified silica monolith. The prepared column was used to perform neutral and ionized solutes separations by pressurized (pCEC). Due to the zwitterionic nature of the resulting stationary phase, the monolithic column provided both electrostatic attraction and repulsion sites for electrochromatographic retention for ionized solutes. Separation of several nucleotides was investigated on the monolithic column. It was shown that the nucleotides could be separated based on hydrophilic and electrostatic interactions between the stationary phase and analyte. Besides, the separation property of the zwitterionic silica monolith was compared with the use of diamine‐bonded silica monolith as stationary phase. As expected, the lysine monolith exhibited a lower retention for the five nucleotides, which was due to the dissociation of the external carboxylic acid groups, leading to electrostatic repulsion with negatively charged solutes. Under the same experimental conditions, separation of the five nucleotides on the zwitterionic column was in less than 8 min, while that on the diamine column was in approximately 60 min. 相似文献
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研究通过对溶胶-凝胶法制备的硅胶整体材料进行研磨、浮选、假晶相转换和水热处理,最终获得了粒径为2~5 μm、孔径为20~60 nm的硅胶颗粒。利用部分含氟的阴离子表面活性剂Capstone FS-66和常用的阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)组成的双胶束模板体系对硅胶基质进行假晶相转换处理;再采用碳酸钠溶液水热处理的方式,进一步扩大孔径。用扫描电镜(SEM)和N2吸附-解吸等温线测量对扩孔处理前后的硅胶整体材料研磨颗粒进行表征,结果清楚地显示了处理前后的形貌变化和差异。随后将含有长链聚乙二醇(PEG)的硅烷键合到扩孔后的硅胶颗粒表面,分别利用元素分析、红外光谱以及热重分析对固定相进行表征,并对固定相进行色谱性能评价。对键合固定相的元素分析和热重分析数据进行分析表明,硅胶表面键合PEG的含量约为8%。研究揭示了利用假晶相转换法与碳酸钠溶液水热处理和长链PEG硅烷修饰的硅胶整体材料颗粒在尺寸排阻色谱分离蛋白质方面的良好分离效果。同时进一步的高效液相色谱评价结果表明,该键合固定相还可用于疏水作用色谱模式分离核糖核酸酶A和溶菌酶,以及可用于亲水作用色谱模式分离吡啶甲酸、左旋多巴、三聚氰胺和邻苯二酚等极性比较强的化合物。研究显示了PEG键合固定相具有多功能性,及其在多模式高效液相色谱分离中的应用潜力。 相似文献
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In this paper, a poly(styrene-octadecene-divinylbenzene) (PS-OD-DVB) monolithic column was prepared in one step by introducing a C18 carbon chain as monomer. N,N-Dimethylformamide and decanol served as porogens to make a homogeneous polymerization mixture in a fused silica capillary (320 microm inner diameter). Its physical and chromatographic properties were compared with those of poly(styrene-divinylbenzene) (PS-DVB) monolithic column, which was also fabricated by in-situ polymerization in a fused silica capillary with the same inner diameter. Six standard proteins were used to evaluate the columns and their potential application for the separation of human hemoglobin was also discussed. It was shown that the PS-OD-DVB and PS-DVB monoliths appeared to have similar efficiency for rapid separation of six proteins within 3.5 min. The PS-OD-DVB monolith was found to have higher loading capacity and higher resolution for the separation of alpha and beta chains of hemoglobin because of the introduction of C18 carbon chains, and shows great potential for the separation of bio-macromolecules. 相似文献
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In this work a new type of chiral monolith silica column was developed for the chiral separation by micro high-performance liquid chromatography (micro-HPLC). The chiral monolith column with a continuous skeleton and a large through-pore structure was prepared inside a capillary of 100 microm I.D. by a sol-gel process, and chemically modified with chiral selectors, such as L-phenylalaninamide, L-alaninamide and L-prolinamide, on the surface of the monolithic silica column. Based on the principle of ligand exchange, these chiral monolithic columns were successfully used for the separation of dansyl amino acid enantiomers, as well as hydroxy acid enantiomers by micro-HPLC. The chromatographic conditions, the enantioselectivity and the performance of columns are discussed. 相似文献
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A silica-based monolithic capillary column was prepared via a sol-gel process. The continuous skeleton and large through-pore structure were characterized by scanning electron microscopy (SEM). The native silica monolith has been successfully employed in the electrochromatographic separation of beta-blockers and alkaloids extracted from traditional Chinese medicines (TCMs). Column efficiencies greater than 250 000 plates/m for capillary electrochromatography (CEC) separation of basic compounds were obtained. It was observed that retention of basic pharmaceuticals on the silica monolith was mainly contributed by a cation-exchange mechanism. Other retention mechanisms including reversed-phase and normal-phase mechanisms and electrophoresis of basic compounds also played a role in separation. A comparison of the differences between CEC and capillary zone electrophoresis (CZE) separation was also discussed. 相似文献