A NEW SEQUENTIAL PROCEDURE FOR THE EFFICIENT AND AUTOMATED LOCATION OF OPTIMUM CONDITIONS IN HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY (HPLC)

A new sequential Optimization Procedure by Search Point (OPSP) based o n Hooke-Jeeves algorithm is developed. The procedure is an automated m ultifactor optimization of conditions for an HPLC separation. Its usef ulness in computer-assisted method development is shown by the experim ental mobile phase optimization of an isocratic reverse phase liquid c hromatography separation of a mixture of six selected pesticides. The relative composition of a ternary mobile phase (Acetonitrile, Methanol , Water) was varied during the optimization process. An objective func tion (OF) which was used as the criterion of quality of the chromatogr aphic separation is described. The performance of this new chromatogra phic method is evaluated either by plotting the map of the separation quality using a Grid Search method or by comparing the results with th e ones obtained by the application of a Modified Simplex method, in bo th cases over the same triangular (Acetonitrile, Methanol, Water) para meter space. The optimum solvent composition for the satisfactory sepa ration of pesticides by application of the OPSP was determined from on ly eleven chromatographic experiments while by applying the Modified S implex or the Grid Search procedure the number of experiments were 15 and 36 respectively.