Retention models of capacity factor with different compositions of organic modifier in RP-HPLC

Abstract

A chromatographic retention behavior of five deoxyribonucleosides (dCyd, dUrd, dGuo, dThd, and dAdo) with respect to the mobile phase composition was studied under isocratic conditions of reversed phase High Performance Liquid Chromatography (RP-HPLC). The volume fraction (F) of organic modifier was changed from 0.05 to 0.30, and to 0.12 for methanol and acetonitrile, respectively. The experimental data of nitro and steroid compound were also considered for comparison of five retention models with various class of samples. The Langmuir-type retention model (k' = A + B/F) with two parameters shows excellect agreements between the experimental capacity factors and calculated values although the values by the log-scale quadratic model with three parameters (log k' = LF(2) + MF + N) are closer. Unlike the other four retention models, the slope B of the Langmuir-type retention model can characterize the properties of solute and organic modifier simultaneously. For each solute, the intercepts A calculated far acetonitrile and methanol as organic modifiers are coincident closely.