Criteria for Comparing the Quality of Chromatograms with Great Variations in Capacity Factors

Abstract

Optimization procedures in chromatography require clear and unambiguous goals. Optimization criteria express such goals in mathematical terms. If the capacity factors vary as a function of the parameters to be optimized, criteria should be selected that allow the simultaneous optimization of the retention and the selectivity. It is demonstrated that the result of an optimization process depends on the optimization criterion selected. For a simple (fictive) example five different criteria are seen to result in five different locations for the optimum. This example will be used to compare the different criteria and to formulate general recommendations for two different situations. An optimization problem in (capillary) supercritical- fluid chromatography is discussed as a practical example.