Examination of the properties of different 20% phenyl‐substituted polymethylsiloxane stationary phases for capillary chromatography

Abstract

Abstract. Three polysiloxanes, each having 20% phenyl substitution, have been evaluated for use as stationary phases in fused silica open tubular columns for gas and supercritical fluid chromatography. The columns were coated with PS-090 which had been treated in an aluminum pan in order to improve immobilization properties, OV-7, and a newly synthesized phase, Polymer S.Excellent columns were prepared with PS-090; however, treatment in the aluminum pan was an uncontrolled process, and the reproducibility of polarity may be questioned. For comparison, OV-7 could not be immobilized, but columns coated with this phase showed good thermal stability. The silanol terminated Polymer S was immobilized via a mechanism involving scission of phenyl groups; thus polarity was decreased after immobilization. However, columns for which Polymer S was immobilized in the presence of a cross-linking reagent maintained their polarity. Such columns showed very good chromatographic performance. These columns were applied to the separation of polynuclear aromatic compounds by GC and to the analysis of extracts from a thermomechanical pulping white water and lichen by SFC.