| 초록 |
Reversed-phase chromatography is an important method for the separation and purification of chemical and pharmaceutical products from dilute mixtures. In order to design a chromatography separation process, equilibrium and mass transfer data must be obtained experimentally. Several limitations have been encountered with conventional techniques for the determination of isotherm data by either batch experiment or an analysis of breakthrough curves. Firstly, each of these approaches requires data from a series of individual experiments for the determination of a complete isotherm and consequently relatively large amounts of the adsorbate is required. Thus, for pharmaceuticals in particular, a lot of cost may be incurred in the provision of sufficient adsorbate for isotherm determinations. Secondly, for commercial adsorbents with particle sizes of approximately 1 mm, the approach to equilibrium is slow. In this case, experiments are time-consuming. Finally the stablity of the adsorbate during experiments may cause error. For example, cephalosporin C is hydrolysed about 10% decomposition per day by a slow first order reaction. From a practical point of view, therefore, an ideal method of isotherm determination for costly pharmaceuticals should contact small quantities of adsorbate with an adsorbent for short time. In this work we examine the accuracy of isotherm parameters and a mass transfer coefficients within the adsorbernt which were estimated from an analysis of HPLC chromatograms and from batch experiments. The procedure involves matching the shape of experimental HPLC chromatogram with that predicted from a simplified set of model equations for a pulse of adsorbate propagating through an HPLC column.
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