Comparative prediction of the retention behaviour of small peptides in several reversed-phase high-performance liquid chromatography columns by using partial least squares and multiple linear regression

The retention behaviour of small standard peptides in reversed-phase high-performance liquid chromatography (RP-HPLC) is evaluated. Chromatographic retention of small peptides highly correlates with the summing of the hydrophobic contributions of their respective amino acid residues. Prediction of peptide retention time is accomplished in four different RP columns (Ultrasphere Octyl, Ultrasphere ODS, Polymeric reversed phase PLRP-S and Nova-pak C-18) under the same chromatographic conditions. The elution profiles of a mixture of 25 small standard peptides are highly correlated among the four RP columns. In addition, RP columns exhibit similar behaviour as far as the pattern of amino acid contribution to the retention of small peptides is concerned. Comparative prediction of peptide retention times is carried out using Multiple Linear Regression (MLR) and Partial Least Squares (PLS) regression. PLS regression provides better prediction ability than MLR. Following the PLS procedure, a reasonable estimation of peptide retention times, after calculating the corresponding amino acid retention coefficients, is possible.