高效液相色谱柱外效应及其修正方法的研究

【作者】 程晖；

【导师】 南碎飞；

【作者基本信息】 浙江大学 ， 化学工程， 2002， 硕士

【摘要】 当今的社会，科技蓬勃发展，科学分析手段日益进步，利用HPLC来检测、定量各种各样复杂成分已经在各国的科研和教育机构迅速普及。由于制造技术的日益成熟，高效液相色谱仪已变得非常精密，检测限越来越小。但是HPLC的应用多为生物、医药、环保等领域，样品的组分极其复杂，因此不可避免地出现色谱峰的重叠及遮盖现象，给色谱峰的准确定量带来了一定的难度。目前各主要的色谱工作站对重叠峰定量的解决方案多是简单的采取中切法。而色谱理论早已指出色谱峰是不对称的，不对称的因素既有热力学方面的，也有动力学方面的。在HPLC仪器更加精密的今天，这种不对称性越来越明显。中切法定量的不科学性也越来越突出，其造成的误差是十分可观的，这就迫使我们寻找一种更为科学的方法。 本文的思路是从影响色谱峰形状的各种因素着手，对原始的色谱峰进行修正，扣除其扩展和不对称性的因素。这样从理论上说，经过处理的色谱峰与原始峰相比，会变得更窄更对称，这时再对重叠峰进行中切法处理，就可以在很大程度上减少简单中切法所造成的定量误差。 在HPLC中，造成色谱峰不对称的原因可以物理的分为柱内效应和柱外效应。由于以下三个方面的原因，本文只考虑柱外效应：1．随着色谱仪器的日益精密，柱外效应相对于柱内效应日益成为色谱峰不对称性的主导因素。2．各HPLC制造商的柱工艺不同，其柱内效应也不同，很难找到一个通用的解决方案。3．柱内效应既涉及到动力学因素，又与热力学因素有关，其模型较为复杂。 本文着重考察了连接管在各种条件下(不同直径，不同长度，不同流速，不同的扩散系数)对色谱流出曲线的影响，我们建立了一个数学物理模型，并使用有限分析方法求解了此模型，模拟了组分在连接管中逐步扩展的过程。在此基础上，本文利用了一个相反的过程修正了连接管等柱外效应对色谱峰形的影响，并用于对苯—甲苯重叠峰的定量计算，得到了较为理想的结果。更多还原

【Abstract】 Nowadays, with the rapid development of technology, the method of scientific analysis is becoming more and more advanced. The HPLC is widely employed to characterize and quantitative analysis a variety of substances by many research and teaching institutes. The HPLC is more sophisticated and the detect limit is small owing to the development of manufacturing technology. Because the HPLC is mainly applied in biology, pharmaceutic and environment protection, and the components of the sample are very complex, so the generation of the overlapped peaks is inevitable, bringing about the difficulty to quantify them accurately. Now the main HPLC station is using the middle-cutting method to quantitative analysis. However, the chromatography peaks are asymmetrical according to the chromatography theory. With the influence of both thermal and kinetic factors, and with the HPLC more sophisticated, the asymmetry is more obvious. The application of the middle-cutting method is unreasonable, and the deviation is appreciable. Therefore, a more acceptable method must be found.The main work was focused on the factors, which cause the asymmetry of peaks. The original peaks are modified according to the asymmetric factors. And theorically, the modified peaks are narrower and more symmetrical compared with the original peaks. Then the overlapped peaks were processed by middle-cutting method, and the deviation can be reduced.In HPLC, the asymmetry of the peaks is caused by columm effect and extra-column effect. We only considered the extra-column effect because of the following three reasons: 1. The extra-column effect is dominant compared with the column effect in the more sophisticated HPLC instrument. 2. The column effect varys with the different manufacturers and the general resolution is hard to establish. 3. The column effect consists of both kinetic and thermal factors, and the model is comparatively complex.In our research, the connection tube was studied under every condition such as different diameters, length, flowing velocity and diffusion coefficient. And theinfluences to the curves of the flowing out were investigated. We established a mathematical model which was solved by finite analytical method(FAM). And the elution of the components in the connection tube was simulated. Moreover, we establish a similar model to modify the actual chromatography peaks, then we process the overlapped peaks with the method of middle-cutting and get reasonable results.更多还原