宽口径填充毛细管液相色谱柱柱尾结构的改进

 设计并评价了尾锥形填充毛细管液相色谱柱,与粘结型柱尾比较,前者柱效高且van Deemter曲线高流速部分的流速-柱效关系明显改善。在折合流速为10～15时,前者的柱效比后者高出30%～50%。谱带的抛物线状的流形在尾锥形柱内得到改善,使色谱峰的对称性有明显提高。比较了两种结构的色谱柱在芳烃快速分析中的分离效果,结果是尾锥形柱的分离性能优于粘结型柱。     

电色谱整体柱的研究进展*

电色谱整体柱是通过原位聚合或固化于柱管内部的方法来制备的一种新型色谱柱.与常规的填充毛细管柱不同的是,其制备方法具有简易性和易于实现色谱填料表面化学性质多样性的特点,已迅速成为优异的毛细管电色谱固定相形式.本文综述了毛细管电色谱整体柱研究的最新进展.     

10°锥角台锥型制备液相色谱柱的放大研究

将10°锥角台锥型液相色谱柱放大至150mm长、入口直径54mm、出口直径27mm,容积为200mL,填料为粒径40～75μm、孔径11nm的C18球形硅胶。流动相在锥型柱内呈现塞子状流形。系统地评价了该柱的分离性能,结果表明：在最佳流速为6mL/min时,以萘峰计,锥型柱的折合理论塔板高度为2.11,柱效下降10%时的样品质量和体积载样量分别为2.1mg和1.7mL,与同长度同体积圆柱型柱相比,柱效提高了20%,质量载样量提高了16%以上,体积载样量提高了19%以上。当进样质量由2.4mg增加到12mg时,对羟基苯甲酸乙酯峰与对羟基苯甲酸丁酯峰的分离度（Rs2）由2.14降到1.71,对羟基苯甲酸丁酯峰与萘峰的分离度（Rs3）由2.91降到2.52;当进样体积由3mL增加到19mL,Rs2由2.23降到1.28,Rs3由2.95降到2.30,但此时的色谱峰峰形仍然高度对称,没有拖尾,有利于从基质中制备分离微量组分。实验结果表明锥型液相色谱柱将具有广泛的应用前景。     

10°锥角台锥型制备液相色谱柱的放大研究

将10° 锥角台锥型液相色谱柱放大至150 mm长、入口直径54 mm、出口直径27 mm,容积为200 mL,填料为粒径40～75 μm、孔径11 nm的C18球形硅胶。流动相在锥型柱内呈现塞子状流形。系统地评价了该柱的分离性能,结果表明: 在最佳流速为6 mL/min时,以萘峰计,锥型柱的折合理论塔板高度为2.11,柱效下降10%时的样品质量和体积载样量分别为2.1 mg和1.7 mL,与同长度同体积圆柱型柱相比,柱效提高了20%,质量载样量提高了16%以上,体积载样量提高了19%以上。当进样质量由2.4 mg增加到12 mg时,对羟基苯甲酸乙酯峰与对羟基苯甲酸丁酯峰的分离度(Rs2)由2.14降到1.71,对羟基苯甲酸丁酯峰与萘峰的分离度(Rs3)由2.91降到2.52;当进样体积由3 mL增加到19 mL,Rs2由2.23降到1.28,Rs3由2.95降到2.30,但此时的色谱峰峰形仍然高度对称,没有拖尾,有利于从基质中制备分离微量组分。实验结果表明锥型液相色谱柱将具有广泛的应用前景。     

生物大分子液相色谱分离中色谱柱长与柱径比的优化研究

用厚度为 1cm、而直径不同的色谱饼 (或饼形色谱柱 )对 7种蛋白质进行了色谱谱分离 ,得出了柱长与柱径比对生物大分子分离度影响不大的结论。还对柱内腔几何体积相同、而柱长 柱径比不同的色谱柱和色谱饼对分离度的影响以及它们压力降作了比较 ,结果表明色谱饼可在几乎不降低分离度的前提下显著降低色谱系统的压力。通过对 1 0× 5 0mmI.D .色谱饼体积和质量负载量以及质量回收率的测定 ,表明色谱饼对生物大分子的分离已达到制备规模。     

弱酸型阳离子色谱柱的制备与应用

采用马来酸酐接枝硅胶的方法制备弱酸性阳离子色谱柱填料.实验证明,该填料制备的色谱柱具有良好的色谱分离性能,可同时分离一、二价金属阳离子,对于常规7种阳离子有很好的分离能力,可应用于离子色谱阳离子分析.用于检测自来水、透析液等实际样品取得了良好的效果.     

不锈钢宽口径填充毛细管液相色谱柱的制备及评价

设计了一种零死体积的柱尾连接方式和一种能使匀浆填料均匀进入色谱柱管内的锥形储料池。详述了以反相 ＯＤＳ为固定相,制备高效稳定的不锈钢宽口径（０．８ ｍｍＩ．Ｄ．）填充毛细管液相色谱柱的方法。系统地考察了填装方向、加压溶剂、匀浆溶剂、匀浆浓度和填装压力等不同因素对柱效的影响。在４０ＭＰａ压强和优化条件下,可重复制得柱效达理论塔板数为７．５×１０４／ｍ。对所测试的样品,色谱峰不对称因子为１．０３～１．１０。     

高效液相色谱整体柱技术研究进展

高效液相色谱整体柱作为一种新型的分离介质,由于其制备工艺简单、易于修饰改性和分离性能优异,近年来引起了人们的广泛关注。聚合物整体柱具有生物相容性好、柱效高、寿命长、选材范围广、重现性好及使用不受p H限制等优势,广泛应用于食品、化工、农业、环境及生物医学领域小分子化合物及蛋白质的分离和检测,显示出较好的应用前景。本文就近10年液相色谱整体柱的制备、改性方法及应用的研究成果进行综述,并对其在不同应用领域的发展前景作了展望。     

阴离子交换聚合物整体柱的制备及其在离子色谱中的应用

以偶氮二异丁腈( AIBN)为自由基引发剂,将甲基丙烯酸缩水甘油酯(GMA)单体和亚乙基二甲基丙烯酸酯(EDMA)交联剂通过原位聚合的方法,在不锈钢管柱(150 mm ×4.6 i.d.mm)中合成为具有一定机械性能和一定孔径结构的聚合物整体色谱柱;利用三甲胺动态修饰反应将整体柱改性为具有阴离子交换功能的整体型离子色谱分离柱.实验优化了制备条件和改性修饰条件,考察了相关离子交换容量、流体动力学参数和色谱性能等.采用直接紫外检测的方法,在205 nm检测波长下,常规阴离子乙酸根、溴酸根、亚硝酸根、溴离子、硝酸根均能得到较好的分离检测.结果表明,该阴离子交换整体色谱柱制备方法简便,成本较低,可以方便地与常规色谱系统进行联用,具有一定分析实用价值和较大的开发前景.     

高效制备液相色谱柱技术的研究进展

本文概述了高效制备液相色谱柱的柱型结构、填料以及柱填充方法等研究的最新进展,讨论了制备柱与分析柱的不同特征,对目前普遍使用的压缩型制备柱的类型、结构及填充方法作了较为全面的评述,总结比较了工业化制备色谱填料不同于分析色谱填料的特点,探讨了高效制备液相色谱柱技术的应用和发展前景.     

Evaluation of Packed GLC Columns for Nanomolar Analysis of Unknowns Lincluding a New Type of Packed Column

Abstract

Fatty acid methyl esters, 2,6-dimethylaniline, and 2,6-xylenol were used for rapid evaluation of the usefulness of packed GLC columns for analysis of unknowns at the nanomolar level. Three types of column construction with three liquid phases of widely varying polarity were tested by the above procedure. A new type of GLC column, a dynamically coated packed column prepared with a surface active agent, was found to yield better overall performance for less polar liquid phases than packed silanized glass or packed stainless steel columns.     

Polyether ether ketone encased monolith frits made of polyether ether ketone tubing with a 0.25 mm opening resulting in an improved separation performance in liquid chromatography

Tiny polyether ether ketone encased monolith frits have been prepared by modified catalytic sulfonation of the inner surface of polyether ether tubing (1.6 mm od, 0.25 mm id) followed by modified formation of organic monolith and cutting of the tubing into slices. The frit was placed below the central hole of the column outlet union and supported by a combination of a silica capillary (0.365 mm od, 0.05 mm id) and a polyether ether ketone sleeve (1.6 mm od, 0.38 mm id) tightened with a nut and a ferrule when the column was packed to prevent sinking of the frit element into the union hole (0.25 mm opening) otherwise. The column packed this way with the frits investigated in this study has shown better separation performance owing to the reduced frit volume in comparison to the column packed with a commercial stainless‐steel screen frit. This study establishes the strategy of disposable microcolumns in which cheap disposable frits are used whenever the column is re‐packed to yield columns of even better chromatographic performance than the columns with commercial frits.     

一种多通道匀浆装填毛细管色谱柱的新装置及应用

针对目前毛细管色谱柱装柱效率低、不同批次装填的毛细管色谱柱之间性能差异大的问题,我们发展了一种多通道匀浆装填毛细管色谱柱的新装置。该装置以液相色谱泵提供压力、采用磁力搅拌保持匀浆液均匀分散,一次可装填多达6根毛细管色谱柱。以牛血清白蛋白(BSA)的胰蛋白酶酶切肽段混合物为样本,选择峰容量、蛋白覆盖率、3个特定离子的保留时间以及毛细管色谱柱柱压为指标,在毛细管液相色谱-质谱联用系统上对装填的反相毛细管色谱柱的性能进行了评价。分别考察了一次装填的6根毛细管色谱柱、两次装填的12根毛细管色谱柱以及一次装填1根与一次装填6根毛细管色谱柱的性能及稳定性。实验结果表明:同一批次装填的6根毛细管色谱柱的性能相近;不同批次装填的12根毛细管色谱柱的峰容量和覆盖率没有明显的区别,但保留时间和毛细管色谱柱柱压的稳定性较差;一次装填1根和一次装填6根毛细管色谱柱柱性能的稳定性与两次分别装填6根毛细管色谱柱的稳定性相近,即采用本装置可显著提高毛细管色谱柱的装填效率且每次装填毛细管色谱柱的数量不会对柱性能产生影响。     

台锥形柱尾的填充毛细管液相色谱柱

首次将台锥形柱尾用于填充毛细管液相色谱柱,并与环氧胶粘的柱尾连接方式进行比较,发现在柱内径≥０．３２ｍｍ时,前者的柱效比后者高出３０％～５０％,且明显改善柱效－流速特性。对比研究了不同内径柱（０．５３ｍｍ,０．３２ｍｍ,０．２５ｍｍ）采用两种尾接方式的塔板高度与流速的关系,对产生差异的原因进行了探讨。     

The Development of Reversed‐Phase Capillary Electrochromatography for the Separation of Steroids

This paper describes the preparation and optimization of packed capillary columns for reversed‐phase separation of steroids with CEC. The fabrication of on‐column frits is considered to be the most important step for obtaining a reproducible packed column for CEC separation. Porous silicate frits were generated in a fused‐silica capillary by heating the silica gel/sodium hydroxide solutions electrically. The optimized conditions involve silica gel (10.8%), sodium hydroxide (5.8%), and heating time (5 sec) with heating voltage (5V) for obtaining a 100‐μ end‐frit that can withstand pressure over 6000 psi. A HPLC pump was utilized to pack the 5‐μm ODS particle slurry into the capillary column. The ODS packed capillaries were then utilized for the separation of four anabolic cholesterols with a capillary electrophoresis system without pressurization of the column. The reproducibility of the packed columns was evaluated by measuring the relative standard deviations of four steroids. The relative standard deviations of migration time for column‐to‐column, day‐to‐day, and run‐to‐run are less than 7%, 2%, and 1% for four steroids, respectively.     

电填充毛细管色谱柱性能的评价

报道了一种毛细管色谱柱的电填充技术,并进行了柱性能的评价研究。实验表明新的填充方法确保了色谱柱的柱效和重现性。     

Influence of Column Material on Efficiency in High Speed Liquid Chromatography

Abstract

The influence of column tubular material on column efficiency in high speed liquid chromatography has been examined. For good reproducibility in HETP, the columns were first packed dry with Corasil I (28–37μ) and then heptane saturated with 3,3′-oxydipropionitrile was flown through the column. When steady state conditions were achieved, the % loading of stationary phase was 1.1%. It was found that column materials of precision bore and seamless stainless steel, aluminum, and copper gave equivalent efficiency results for retained and unretained components. Teflon coated aluminum columns were not reproducible, in regard to HETP.     

Disposable microcolumns with welded metal frits

This study reports the preparation of disposable microcolumns with welded metal frits for the first time. First, the bottom of glass‐lined stainless‐steel tubing of 30 cm length, 1.6 mm od, and 0.5 mm id was welded with a stainless‐steel screen frit of 1.6 mm diameter. A micro‐welding machine was used for this. Next, the column was connected to a slurry packer and packed with porous silica particles. Then, the inlet of the column was carefully welded with another frit. The column was tested for separation of a test mix composed of phenol, 2‐nitrophenol, acetophenone, aceanilide, and benzamide. Another column of the same physical dimension was also prepared with frits that were not welded to the column. The chromatographic performances of the two groups of columns (welded frits versus non‐welded frits) were examined. The columns of welded frits showed ca. 18% better separation efficiency (number of theoretical plates) than those of non‐welded frits.     

Single fiber-in-capillary annular column for gas chromatographic separation

A method for preparation of a stationary phase-adjustable column with in-column stationary phase-coated fused-silica fiber annular column was successfully developed. The surface of a 0.12 mm o.d. bare optical fiber was first coated with a stationary phase and then inserted into a fused-silica capillary (non-coated or coated) as an annular column for gas chromatographic study. The optical fiber and capillary were coated with polydimethylsiloxane (SE-30) and polyethylene glycol 20M (PEG-20M) as nonpolar and polar stationary phases, respectively. Among the investigated annular and open tubular columns, the PEG-20M-coated fiber-in-PEG-20M-coated capillary annular column showed the highest column efficiency with a minimum plate height of 0.35 mm and an optimum gas velocity of 25 cm/s. When a SE-30/PEG-20M-coated fiber-in-uncoated capillary annular column was applied to separate a 9-component complex mixture, the total analysis time was 5.3 min and the column length was 12 m. By contrast, when a SE-30-coated fiber-in-PEG-20M-coated capillary annular column was used to separate the same 9-component mixture, the analysis time was reduced to 3.5 min and the column length was shortened by half to 6 m. Our results show that the stationary phase-coated fiber-in-stationary phase-coated capillary annular column is a better choice for gas chromatographic separation as it is more efficient and flexible. In addition, the proposed annular column design provides flexibility in using two or even more types of stationary phases to achieve optimal analytical separation.