Reversed-phase liquid chromatographic separation of complex samples by optimizing temperature and gradient time III. Improving the accuracy of computer simulation

Previous studies have shown that four experimental runs, where both tempera ture T and gradient time t(G) are varied, can be used for the reliable pred iction of separation as a function of these two variables (two-dimensional optimization). Computer simulation (e.g., DryLab) can then be used to predi ct "optimized" conditions for maximum sample resolution using either isocra tic or gradient elution. Samples that contain a large number of components (e.g., n>15-20) present a greater challenge. Resolution for these more comp lex samples is often quite sensitive to small changes in T or t(G), in turn requiring greater accuracy in predictions that result from computer simula tion. In the present study of several samples, we have examined computer si mulation errors that can arise from inexact expressions for retention time as a function of T, t(G) or isocratic %B. Resulting conclusions are applica ble to both complex and simpler samples, in either one- or two-dimensional optimization. Means to anticipate and minimize the impact of these predicti ve errors are examined. (C) 1999 Elsevier Science B.V. All rights reserved.