A multifactor optimization strategy was utilized to predict the isocratic HPLC separation of nine phenols. The retention behavior was studied as a function of changing eluent (methanol ? acetic acid) composition. The predicted and measured retentions are in rather good agreement. To locate the optimum in the factor space, the normalized resolution product criterion was applied. In virtually every case, the resolution is limited by the separation of the 2-chlorophenol and 2,4-dinitrophenol pair.

The parameters for the development of a chromatographic (HPLC) method and its validation are discused in the paper. Chromatographic analysis involves a multi-step procedure consisting of sample collection, pretreatment instrumental measurements and data processing. Emphasize was placed on the instrumental part of the analysis presuming that the contributions of the other variables were minor. The roles of precision, accuracy, detection limit, quantification limit, specificity, selectivity, range, linearity and robustness, as well as system suitability in the analytical application of chromatography were described. Recommendations for the validation of these parameters according to ICH and FDA guidelines are given. The criteria of validation described above can be almost completely applied to other instrumental chromatographic techniques such as GC, GC-MS, HPTLC, etc