Performance Characterization of Multi-Solvent Mobile Phase Systems in RP-HPLC by Multi-Criteria Decision Making Illustrated by the Comparison of Ternary and Quaternary Solvent systems

Comination of the Triangular Mixture Design Statistical Technique (TMDST) and Multi-Criteria Decision Making (MCDM) allows the evaluation of the performance of multi-solvent mobile phase systems for RP-HPLC with respect to two criteria simultaneously. If the minimal resolution of two adjacent peaks, Rsmin, and the retention time of the last peak of a chromatogram, kmax, are used as criteria for the optimization, then one can compare multi-solvent mobile phase systems by their MCDM plots. The solvent system that can give a charomatogram with an acceptable resolution in shortest possible analysis time for a given searation problem can be selected. Multi-solvent mobile phase systems that need a longer analysis time to obtain the same acceptable resolution for this separation, can be ruled out. This is demonstrated by the comparison of the performance of ternary and quaternary iso-eluotropic mobile phase systems in the separation of a mixture of benzene derivatives on a RP octyl column