不锈钢宽口径填充毛细管液相色谱柱

 设计了一种零死体积的二通式柱尾结构和一种使匀浆填料均匀进入色谱柱管内的储料池 ,研究了制备内径在 0 5mm～ 1 0mm的不锈钢宽口径填充毛细管液相色谱柱的方法。详述了以不同牌号、规格的反相ODS类固定相制备的不同柱长的色谱柱的性能。通过折合板高 /折合流速关系和不对称因子对柱性能进行了评价 ,结果表明 ,该方法制备的色谱柱柱效达到理论值的 75 %以上、RSD为 6% ,稳定性也很好。将其应用于抗癫痫药物和氯苯类化合物的分析 ,结果令人满意。     

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。     

磁场辅助毛细管电色谱

磁场辅助毛细管电色谱是液相色谱研究领域中出现的新技术．它利用外加磁场的引力将置于毛细管内的具有磁响应性的硅胶微球或四氧化三铁微球固定在管内任意位置．磁场固定微球聚集体既可用作填充柱,直接用于电色谱分离;也可用作柱筛,用于填装由商品色谱填料组成的色谱柱．这一技术的优势在于制备简便易行,柱管可以再生使用,适合于微流控芯片上柱筛或柱床的制作．本文简要评述磁场辅助毛细管电色谱的进展,包括磁性色谱填料的制备,磁场固定柱床电色谱,磁性柱筛电色谱及毛细管柱内柱结构参数的测定等方面．     

新型微填充柱－毛细管柱二维色谱系统过程的动力学研究

从色谱动力学角度对新型微填充柱－毛细管柱二维色谱系统过程中双柱条件与流出曲线及柱效之间的依赖关系加以系统研究。结果表明：由于双柱条件之间存在关联，双柱系统流出曲线特征与单柱系统存在一定的差异，流出曲线一阶矩和二、三阶中心矩以及双柱系统的柱效皆由预柱和主柱条件综合确定。     

Alltech集束毛细管柱和常规毛细管柱的比较

对集束毛细管气相色谱柱的色谱性能,如流速对柱效的影响、柱温对柱效的影响、柱容量等进行了考察,并将其对典型火炸药成分ＤＮＴ,ＴＮＴ的分离与常规毛细管气相色谱柱进行了比较。结果表明,集束毛细管气相色谱柱综合了填充柱与石英毛细管气相色谱柱之优点,弥补了二者的不足,是一种柱容量较大且分离效能好、可以在高载气流速下操作的新型气相色谱柱。     

新型微填充柱－毛细管柱二维色谱系统过程的动力学研究

 从色谱动力学角度对新型微填充柱－毛细管柱二维色谱系统过程中双柱条件与流出曲线及柱效之间的依赖关系加以系统研究。结果表明：由于双柱条件之间存在关联，双柱系统流出曲线特征与单柱系统存在一定的差异，流出曲线一阶矩和二、三阶中心矩以及双柱系统的柱效皆由预柱和主柱条件综合确定。     

对甲苯磺酸正丁铵毛细管色谱柱的制备及性能考察

用动态涂敷法制备了对甲苯磺酸正丁铵玻璃毛细管柱柱１（固定液浓度为７．５％,柱尺寸为３５ｍ×０．３５ｍｍｉ．ｄ．）和柱２（固定液浓度为９．２％,柱尺寸为３５ｍ×０．３０ｍｍｉ．ｄ．）,所用溶剂是丙酮和甲醇（２：１Ｖ／Ｖ）的混合溶剂,并对柱性能进行了考察。结果表明,这种色谱固定相具有较强的极性并对饱和烃、芳香烃、饱和酸、芳香酸、极性异构体等具有良好的分离效果。     

中孔分子筛在气固色谱中的应用

将中孔分子筛这一新材料应用于气固色谱，可以分离脂肪烃，芳烃，卤代烃以及一些酮类化合物。对这种中孔分子筛柱的柱效，定量解吸等情况进行了考察，并与传统的气固色谱柱和一些常用气液色谱柱进行了对比。在填补中孔材料气固色谱吸附剂空白方面作了有意义的探讨。     

多壁碳纳米管作为气相色谱固定相的性能研究

将甲烷催化裂解法生产的经过纯化的多壁碳纳米管(PMWCNTs)、活性炭、石墨 化碳黑(Carbopack B)分别填装成气相色谱填充柱,比较它们分离烷烃、芳香烃、 卤代烃、醇、酮、醚、酯类的性能。分别在PMWCNTs和Carbopack B上涂清5%(w/w) 的Carbowax 20M,填装成气相色谱填充柱后,比较它们分离醇、酮、醚、酯、有机 酸类的性能。结果表明,PMWCNTs是一种性能优异的气相色谱固定相。与相同比表 面积的Carbopack B石墨化碳黑相比较,它有更强的保留能力,适合于分析沸点相 对较低的化合物;具有更均匀的表面,表现为极性化合物亦可得到对称的峰形;理 论塔板数较小。此外,和Carbopack B一样,PMWCNTs涂清5% (w/w) Carbowax 20M 后可用来分离极性化合物,甚至是强极性的小分子有机酸。     

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。     

填充条件对半制备柱性能影响的机理研究

对稀匀浆法填充半制备柱(Ф10 mm×100 mm)的过程进行研究,并用正交法对柱填充条件进行了优化,考察了压力、匀浆液组成、匀浆液体积对半制备柱填充效果的影响.由柱效和分离度定义式中的参数入手,讨论填充条件对柱性能的影响.通过计算总孔隙率ε_t、内部孔隙率ε_p、外部孔隙率ε_e、Van-Deemter曲线、吸附等温线等参数,发现填充压力对填充密度的作用最大,是最重要的影响因素;匀浆配比和匀浆体积共同影响其填充的均匀性.在压力11 MPa,流速275 mL/min,120 mL纯乙醇为匀浆液的条件下得到了最好的填充效果.     

Mesoporous polybutadiene-modified zirconia for high-temperature packed capillary liquid chromatography: column preparation and temperature programming stability

In the present study, three different methods for packing of 3 microm PBD-ZrO2 particles in 0.5 mm i.d. glass-lined stainless steel columns have been examined. The two first methods were based on a traditional downstream high-pressure technique using tetrachloromethane (Method I) or aqueous Triton X-100 (Method II) as slurry solvents, while Method III was an upstream high-pressure flocculating method with stirring, using isopropanol both as the slurry and packing solvent. Method I was found to be superior in terms of efficiency, producing 0.5 mm i.d. x 10 cm columns with almost 90,000 plates m(-1) for toluene (R.S.D. = 8.7%, n = 3), using a slurry concentration of 600 mg ml(-1), ACN-water (50:50 (v/v)) as the packing solvent and a packing pressure of 650 bars. For Method I, the slurry concentration, column i.d., column length and initial packing pressure were found to have a significant effect on column efficiency. Finally, the long-term temperature stability of the prepared columns was investigated. In isothermal mode, using ACN-20 mM phosphate buffer, pH 7 (50:50 (v/v)) as the mobile phase, the columns were found to be stable for at least 3,000 void volumes at 100 degrees C. At this temperature, the solute efficiencies changed about 5-18% and the retention factors changed about 6-8%. In temperature programming mode (not exceeding 100 degrees C), on the other hand, a rapid decrease in both column efficiency and retention factors was observed. However, when the columns were packed as initially described, ramped up and down from 50 to 100 degrees C for 48 h and refilled, fairly stable columns with acceptable efficiencies were obtained. Although not fully regaining their initial efficiency after refilling, the solute efficiencies changed about 19-28% (32-37%) and the retention factors changed about 4-5% (13-17%) after running 3,000 (25,000) void volumes or 500 (3,900) temperature programs.     

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。     

Microbore HPLC column performance and temperature programming capabilities

Microbore columns (1 mm i.d.) are compared to conventional 4.6 mm i.d. columns with respect to speed, efficiency and sensitivity. If column lengths, particule diameter, packing efficiency, mobile phase, and linear velocity are the same, most chromatographic properties such as speed (analysis time), efficiency, pressure drop, and sensitivity are the same. The major differences are the column volumes, the void volumes, and the volumetric flow rates for equal linear flow velocities. The low flow rates of microbore columns (30 to 200 μl/min), conserve solvent and make for easier interfacing to other instruments such as MS, NMR, or FTIR. Temperature programming of microbore HPLC columns produces faster analyses for large k′ values, increased sensitivity (due primarily to sharper peak shape), and increases the range of compounds which can be handled in an isocratic mode.     

半制备色谱柱装填条件的选择

填充技术是影响柱性能的重要因素,但关于半制备柱装填的报道很少.本论文主要对干法和匀浆法装填的半制备柱(φ10×200mm)的性能进行了对比,并对两种方法的装填条件进行了选择.实验结果表明匀浆法装填柱的重现性和柱性能明显优于干法装填的柱.在匀浆法填充中,乙醇为匀浆溶剂,匀浆体积为120mL,冲洗流速为330mL/min,装填时间为20min时所填柱的性能最好.     

A comparative study of microbore reverse-phase columns

A procedure for packing reverse-phase microbore columns using moderate pressure is described. Columns packed from different manufacturer's tubing are compared with commercially available columns. A method for coupling the column to the injection valve is suggested. The effect of detector cell volume on overall efficiency of the system is also examined.     

Temperature effects on nano-LC column packing technology

We investigated the effect of temperature on the packing procedure of nano-LC columns (up to 50 cm) and on their performance. Several slurries of stationary phase were prepared using different solvent mixtures. Their stability was evaluated at several temperatures: 70°C, 50°C, and room temperature. At the higher temperature (70°C) the suspensions resulted to be stable for a longer time. For each slurry, we compared nano-LC columns packed with ultrasounds at 70°C and at room temperature. All the columns were tested with a standard mixture at 70°C, to reduce the solvent viscosity and the backpressure. Main chromatographic parameters such as the asymmetry factor, As, the reduced plate high, h, pattern in a Van Deemter plot, the total porosity, ε(t), and the permeability, k, were calculated and discussed. One of the nano-LC columns was used to separate a mixture of pesticides in a LC-MS system with an electron ionization LC-MS interface (Direct-EI). From our knowledge, this is the first study on the role of temperature in the efficiency of slurry-packing procedure.     

Semimicro Size Exclusion Chromatography For Oligomers. I. Column Packing Procedure

Abstract

Polystyrene gels of a particle diameter 10 ± 2 μm for the use in oligomer separation were packed into 1.5 mm i.d. × 25 cm length columns by the balanced density slurry-packing technique under a constant flow rate of 500 μL/min. The slurry solvent was a mixture of toluene and chloroform (50.5/49.5, v/v). The example of the number of theoretical plates (N) of these columns was 8600 plates/25 cm (HETP = 29.1 μm) at flow rate of 40 μL/min by injecting 1 μL of 0.5% benzene solution. Sixteen columns were connected and the overall value of N was 103000 plates/4 m. A typical example of oligomer separation was demonstrated. A constant-flow technique is preferable to a constant-pressure technique. When two or three column blanks were packed together, the columns located at the outlet of the packer-column assembly had higher values of N. Optimum flow rate of the slurry solvent when three column blanks were packed together lay between 400 and 500 μL/min. The packing efficiency, that is, the probability of getting valid columns was about 60%. Viscous slurry solvents were not effective to get efficient columns. To pack gels in the less swollen state gave sometimes efficient columns. Pressure monitoring in progress of packing was very effective to foresee the column efficiency.     

High resolution liquid chromatography with a packed micro glass capillary column

Single, long columns (1–5 m) can be prepared efficiently using reversed phase packings (3–10 μm particle diameter). 1-m columns packed with 3 and 10 μm packing provide 110 000 and 50 000 theoretical plates, respectively. Very efficient columns can resolve highly complex mixtures and difficult-to-separate compounds. Temperature gradient elution is a powerful technique for LC with microbore columns.