【作者】 徐丽；

【导师】 冯钰锜；

【作者基本信息】 武汉大学 ， 分析化学， 2004， 硕士

【摘要】 毛细管电泳(CE)和毛细管电色谱(CEC)具有高效、快速、样品用量小、溶剂消耗少和自动化程度高的特点使其成为快速崛起的新型微分离分析技术，在生物医学、药学、生物化学及环境等领域有巨大的应用潜力。它的发展依赖于电泳和电色谱理论的完善，仪器技术的改进和柱技术的发展。要使CE和CEC成为象HPLC那样的常规分析方法，不仅需要有高的选择性，还需要有好的重现性和稳定性。毛细管柱是决定分析分离性能的关键，表面修饰涂层不仅决定电渗流性质，而且能引入对溶质有保留的功能基团，增加选择性。研究适于CE和CEC的制柱方法和技术，制备柱容量大、选择性高和重现性好的毛细管柱，对促进CE和CEC理论和应用的发展都具有重要意义。毛细管管壁修饰技术的研究是CE和CEC领域的前沿研究课题。本论文研究了毛细管内壁修饰方法及其在CE和CEC中的应用。本论文包括如下主要研究内容。 1．评述了离子涂层毛细管电泳和电色谱的应用研究进展。 2．利用溶胶凝胶技术改进了二氧化锆涂层毛细管的制备方法，并系统的研究了非水体系中(甲醇以及甲醇和乙腈的混合溶剂)二氧化锆涂层毛细管在不同条件下的电渗流行为。二氧化锆涂层毛细管表现出双向电渗流，其方向和大小都和体系的性质有关，如pH~*，溶剂组成，电解质(Tris和醋酸铵)。并且二氧化锆涂层毛细管的pI随着乙腈含量增加变大。用生物碱作为探针考察了非水体系中二氧化锆涂层毛细管的电泳性能。溶剂组成对于分离度和选择性的影响也做了考察，同时在相同条件下与非涂层毛细管上的分离做了比较。 3．利用溶胶凝胶技术将有序介孔二氧化钛膜引入到毛细管内壁对其进行了涂层改性。在不同的有机体系中系统的考察了其电渗流性质，如甲醇，甲酰胺，N，N-二甲基甲酰胺以及甲醇和乙腈的混合溶液。二氧化钛涂层毛细管在不同条件下表现出不同的电渗流性质，与各种参数相关，如溶剂组成，pH~*，电解质(Tris和醋酸铵)。同时用生物碱作为探针考察了非水体系中二氧化钛涂层毛细管的电泳性能。在相同条件下与非涂层毛 细管上的分离做了比较。4.利用溶胶凝胶法和化学键合法制备了非高聚物有机磺酸基涂层毛细管。 溶胶凝胶法，通过水解三甲氧基琉丙基硅烷和四甲氧基硅烷得到溶胶， 然后将此溶胶涂覆到毛细管管壁老化;化学键合法则直接将三甲氧基疏 丙基硅烷键合到毛细管内壁。经过上述处理后，毛细管经过30%HZOZ 氧化得到磺酸基涂层毛细管。用两种方法制备的涂层毛细管的电渗流在 所考察pH范围内基本上保持恒定，比未涂覆毛细管大。通过比较两种 方法制备的涂层毛细管电渗流的大小，对硅轻基的屏蔽程度以及制备方 法的重现性，化学键合法的涂层效率要高于溶胶凝胶法。另外还考察了 电解质浓度，甲醇含量尤其是在水一甲醇体系中pH*对电渗流的影响。 最后在6.5分钟之内用毛细管电泳模式实现了七种有机酸的分离，并且 用开管毛细管离子交换电色谱模式对生物碱进行了分离。5一种新的大环化合物一葫【7]环联脉首次作为添加剂在毛细管电泳中得到 了应用。与其他的大环化合物，如冠醚，环糊精，杯芳烃等相似，葫「7] 环联脉能够通过它的空腔与各种客体分子形成包合物。因此可以预料葫 【7]环联脉能够象其他的大环化合物一样用来改变毛细管电泳中的选择 性。在运行过程中，葫[71环联脉在所考察的pH范围内带正电荷，能够 吸附到毛细管管壁上，从而体现出反向电渗流行为。中性硝基苯类化合 物，硝基甲苯，硝基苯酚，硝基苯胺以及甲基苯胺等几种位置异构体作 为探针在各种条件下考察了葫【7]环联脉作为添加剂对其分离的影响，同 时提出了可能的分离机理。更多还原

【Abstract】 Capillary electrophoresis (CE) and capillary electrochromatography (CEC) are promising microseparation analysis techniques; they have the advantages of high efficiency, high speed, small sample consumption and high automation level. The development of CE and CEC is dependent on the improvements in instrumentation design, column technology and understanding of the underlying phenomena. However, it has a long way to go to become the routine analysis method as HPLC with high selectivity, good reproducibility and stability. The nature of capillary is critical for the separation. Based on these observations, the present author intends in this thesis to develop some fabrication techniques for ionic coating capillaries, and investigate their applications in CE and CEC. In addition, a novel macrocyclic molecule, cucurbit[7]uril, is for the first time proposed as an additive for CE separation.1.In Chapter 1, the development of the ionic coating for capillary electrophoresis and capillary electrochromatography is reviewed.2. In Chapter 2, a zirconia-coated capillary is prepared by means of sol-gel technique. Its electroosmotic flow (EOF) properties are investigated in a variety of nonaqueous media (methanol and mixtures of methanol and acetonitrile). The zirconia-coated capillary exhibits the switchable EOF whose direction and magnitude are strongly dependent on the properties of nonaqueous solvents composition, their apparent pHs (pH*), and the electrolytes used (hydroxymethyl aminomethane and ammonium acetate). It is found that the isoelectric point (pI) of the zirconia-coated capillary move to higher pH* with increasing acetonitrile content from 0 to 75%(V/V) when tris (hydroxymethyl) aminomethane is used as an electrolyte. The nonaqueous capillary electrophoresis (NACE) separations of several alkaloids are investigated in the positively charged zirconia-coated capillary. The effect of solvent composition on the separation resolution and selectivity is also studied. In addition,comparison of separation between coated and uncoated capillaries in nonaqueous media is performed.3. In Chapter 3, an ordered mesoporous titania film is introduced to coat a capillary by means of sol-gel technique. Its electroosmotic flow (EOF) property is investigated in a variety of nonaqueous media (methanol, formamide and N, N-dimethylformamide and mixtures of methanol and acetonitrile). The titania-coated capillary exhibits distinctive EOF behavior whose direction and magnitude are strongly dependent on various parameters such as the solvent composition, apparent pHs (pH*) and the electrolytes. The nonaqueous capillary electrophoresis (NACE) separation of several alkaloids is investigated in the positively charged titania-coated capillary. Comparison of separation between coated and uncoated capillaries under optimum nonaqueous condition is also carried out.4. In Chapter 4, two new methods, sol-gel and chemical bonding methods, are proposed for preparation of sulfonated fused-silica capillaries. In the sol-gel method, a fused-silica capillary is coated with the sol solution obtained by hydrolysis of 3-mercaptopropyl-trimethoxysilane (MPTS) and tetramethoxysilane, and followed by age; while in the chemical bonding method, a capillary is chemically bonded directly with MPTS. Then, the both resulting capillaries are oxidized with an aqueous solution of hydrogen peroxide solution (H2O2)(30%(m/m)) to obtain the sulfonated capillaries. The electroosmotic flow (EOF) for the sulfonated capillaries is found to remain almost constant within the studied pH range, and be greater than that of the uncoated capillary. However, the coating efficiency of the capillary prepared by chemical bonding method is higher than that by sol-gel method, by comparing their magnitude of the EOF, the degree of disguise of the silanol and reproducibility of prepar更多还原