Selection of adequate optimization criteria in chromatographic separations

Computer-assisted optimization of chromatographic separations is still a fruitful activity. In fact, advances in computerized data handling should make the application of systematic optimization strategies much easier. However, in most contemporary applications, the optimization criterion is not considered to be a key issue (Vanbel, J Pharm Biomed, 21:603–610, 1999). In this paper, an update of the importance of selecting adequate criteria in chromatographic separation is presented

Criteria for optimizing the separation of target analytes in complex chromatograms

Optimization procedures require adequate criteria to assess the quality of the separation. So far, the vast majority of reports on the subject deal with the situation in which all peaks need to be separated ('complete optimization'). In practice one of the most important requirements for optimization criteria is their ability to deal with limited optimization, i.e. with situations in which only a limited number of solutes in a sample is relevant. In this paper, the adaptation of the most widely used optimization criteria to limited optimization is discussed. Among the most useful criteria are the minimum resolution and the calibrated normalized resolution product. The characteristics and objectives of these two criteria are discussed in detail. The case of non-ideal separations (featuring asymmetrical peaks and/or peaks of vastly different areas) is also investigated. The discussion and evaluation of optimization criteria are based on simulated and experimental data obtained during HPLC optimization studies

Chemometric Optimization in Drug Analysis By Hplc - a Critical-evaluation of the Quality Criteria Used in the Analysis of Drug Purity

Optimization procedures require adequate response criteria to assess the quality of each chromatogram obtained during the process. The objective of this paper is to evaluate the possibility of using different resolution functions, in the chromatographic separation of a drug and its impurities (particularly the impurity just eluted after the drug). This study shows the limits of some resolution expressions. The interest of the simple DELTAt criterion, the difference between retention times, is presented in this paper

Criteria for Developing Rugged High-performance Liquid-chromatographic Methods

An approach is described that allows the ultimate ruggedness of chromatographic methods to be rigorously included as an objective from the outset of systematic method development. Ruggedness criteria are defined as derivatives of other (typically resolution-based) criteria. Numerical estimates of ruggedness criteria can readily be obtained during selectivity optimization. It is necessary to consider ruggedness simultaneously with other objectives of the separation using multi-criteria decision making (MCDM) procedures. Three MCDM methods were considered in this work, viz., Pareto-optimality (PO) plot, Derringer's desirability function and the multiple threshold approach (MTA), The characteristics of these three methods are discussed and the feasibility of developing rugged separations by systematically varying the pH acid solvent composition is demonstrated