Comparison of models and designs for optimisation of the pH and solvent strength in HPLC

Two designs, the one selected with the algorithm of Kennard and Stone and the D-optimal design, and two linear models are compared while optimising separation in RPLC by varying the pH and the solvent strength of the mobile phase. As a practical example the separation of a mixture of β-blockers is applied. To ease the selection of the number of experiments of a design while applying the algorithm of Kennard and Stone, a variant of this algorithm is proposed.