Evaluation of dead time calculation in reversed-phase liquid chromatography using a multiparametric mathematical method

In reversed phase liquid chromatography (RP-HPLC), the validity of a multip arametric non-linear least-squares regression iterative method for the dete rmination of the column dead time t(M) and the regression parameter (slope b), based on the use of alkan-2-ones, alkyl aryl ketones, and 1-nitroalkane s has been evaluated. The determination of t(M) and b has been extensively studied for two mobile phase systems acetonitrile-water and methanol-water on seven octadecyl-(18) and one octyl C-8 analytical columns. The calculate d tM and b values were compared with those obtained by Guardino's and Grobl er's methods. The influence exerted thereon by the nature of the homologous series, the mobile phase composition, and the packing materials were inves tigated.