Quantitative structure-retention relationships in reversed-phase liquid chromatography using several stationary and mobile phases

Quant. structure-retention relations (QSRRs) were employed to study retention mechanism of reversed-phase liq. chromatog. (RPLC). Two C18 and 2 C8 columns were used with mobile phases contg. MeOH, MeCN, and THF in concns. ranging from 40 to 90 (vol./vol.)% in H2O. QSRR equations derived are generally characterized by a satisfactory quality of fit, although missing data or a low av. retention can decrease the goodness-of-fit. In agreement with literature the most important retention descriptors appeared to be the analyte's mol. vol. and its hydrogen-bond accepting basicity, but also the polarity/polarizability, hydrogen-bond donating acidity, and excess molar refraction showed statistical significance in several cases. Relatively small, but significant differences between the 2 C18 stationary phases were obsd. The differences between C8 and C18 column types were more pronounced. The influence of the mobile phase on regression coeffs. is more difficult to interpret, because of adsorption of mobile phase constituents by the stationary phase. However, the importance of this partitioning of H2O and modifier is illustrated by the practically identical trends in b values for the 3 modifiers studied, while the trends in v values are significantly different. Principal component anal. of the QSRR regression coeffs. demonstrated the prevailing role of the mobile phase for chromatog. properties of the RPLC systems studied as compared to the stationary phase. [on SciFinder (R)]