Study Of Competitive Isotherm In Nonlinear Chromatography

Isotherm is the core of nonlinear Chromatography, and the accurate determination of it is very important. For the system of a single component, the determination method is mature. There are several traditional methods used to measure competitive isotherms of binary system, but it is difficult to determine it by these methods accurately. Based on the theory of the predecessors, a new theoretical method, the frontal velocity analysis method, is presented by Prof. Yang, and it is studied in more detail in this paper. The new method is used to determine the competitive isotherms of 2-phenylethanol and 3-phenylpropanol, p-dihydroxy-benzene and resorcinol on ODS-silica, and the results obtained are compared with that from a traditional method-the rectangular pulse method in an effort to validate the new one's accuracy and applicability. The comparison shows that the competitive isotherms obtained from the two methods are in general agreement, but the frontal velocity analysis method is simpler, faster and more economic.The success of the new method, the frontal velocity analysis method, to determine the competitive isotherm of the binary system makes us try to expand it to the measurement of the competitive isotherm for the ternary system. At present, only one method is usedin that system, i. e. the rectangular pulse method. In this paper, the calculation equation of the new method is given and it is applied to determine the equilibrium adsorption data for benzyl alcohol, 2-phenylethanol and 3-phenylpropanol on ODS-silica, and the results obtained are compared with that from the rectangular pulse method. The comparison shows that the new method not only has the advantages of a greater experimental simplicity, of being faster and of being more economic but also gives the reliable results for the determination of ternary competitive isotherms.The frontal velocity analysis method, which can determine accurately the competitive isotherm, will speed greatly the development of the nonlinear chromatography and the optimization process by the numerical method, which has considerable saving in the optimization of new separations ?After the study of the isotherm, a new method is presented to synthesize the papain chrial stationary phase, meanwhile, the kinetics characteristics of the immobilized papain is also investigated. The work described here is done in order to separate chiral medicine and to determine their competitive isotherms on enzyme chiral stationary phase.