| Protein folding remains a bottle-neck issues in the down-stream technology in biotechnology. As a new method, refolding chromatography can improve the bioactivity yield and simultaneously accomplish its purification, so it has been paid much attention in recent years. The interface of liquid-solid in liquid chromatography (LC) gives main contribution to protein refolding, so the impacts of the solute adsorption in the liquid-solid systems were investigated firstly. Then the refolding of protein in the ion-exchange chromatography (IEC), hydrophobic interaction chromatography (HIC) and size-exclusion chromatography (SEC) was studied. The thesis includes eight parts as the follows:1. Review: Interfacial phenomena are encountered broadly in the nature. Adsorption at the interface of liquid-solid systems is more complex and important than that of gas-solid systems. It was reviewed about the importance of studying the adsorption in liquid-solid systems, and specialty and difficulty of the liquid-solid interface and development of recently theoretical studies. Protein folding is a subject of fundamental and practical importance. Though much effort has been expended to solve this problem, no universal method has been established. From the thermodynamic hypothesis and kinetic controlling, a fundamental refolding strategy was introduced. All kinds of method and development based on the strategy were reviewed. 172 references were listed.2. Based on the stoichiometric displacement theory for adsorption (SDT-A), a new adsorption isotherm that relates to the amount of solute adsorbed to the solvent concentration in bulk solution is firstly proposed. The obtained equation may be simplified to an expression containing two, three, and four parameters according to different assumptions. The equation with two parameters, valid for low concentrations of solute, is a log-log linear relationship. The equations with three and four parameters are valid as the adsorbed amounts are larger and show non-linear logarithmic relationships. Tests with a homologous series of aromatic alcohols by frontal analysis (FA) in reversed-phase liquid chromatography (RPLC)demonstrate that experimental results fit those equations well.3. Based on the SDT-A of solute, an equation expressing the linear relationship between the affinity of component to adsorbent, Ba, and the logarithm of the molar concentration of solvent in the bulk solution employed, logaD was derived. The derived equation was tested by the derivatives of benzene under different methanol concentrations by FA of RPLC. A satisfactory result was obtained. Morever, the n and q terms' values (moles of the solvent separately released from the adsorbent and solute, respectively, as one mole of solute is adsorbed) which are the fractions of the stoichiometric parameter Z (Z- n +q), are very useful but hard to obtain only by RPLC alone. However, both were obtained from this relationship and tested with the presented method. The SDT-A, describing the adsorption process, and the SDM-R, describing the retention process, were firstly unified theoretically. It is proved that there exists a linear relationship between the logarithm of capacity factor logA:' in SRT-R and Bain SDT-A. The expression of the concentration convergent point of the homologue was further derived and validated.4. The Langmuir equation, originally derived for gas-solid system and only a quantitative equation in this system, has been widely used to describe empirically solute adsorption from solution for almost a century. In this research, based on various interactions among components in liquid-solid adsorbed system, and by using the SDT-A, the Langmuir equation for solute adsorption from a liquid-solid adsorbed system was firstly theoretically derived and called as Extended Langmuir equation. The parameters in the Extended Langmuir equation were related to that of the stoichiometric displacement equilibrium, thus the former can be extended to describe solute adsorption under v...
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