Classification of reversed-phase materials by means of selected chromatographic data

Abstract

Using n-heptane as eluent a direct linear correlation was found between the logk’ values of various polar test compounds and the silanol content determined by the methyllithium method. The peak asymmetries pass through a maximum at a medium silanol content. Peak asymmetries and logk’ values depend also on the chain length of the bonded alkyl group. A computer program was used to classify 25 home-made RP materials, 7 commercial products and the starting silica to achieve a hierarchical classification of them. The arrangement provides some detailed information about the presence and the effect of silanol groups.