Crosslinked methylphenylsilicones as stationary phases for capillary gas chromatography

Summary

Methyl(phenyl)silicones offer useful selectivities when used as stationary phases in gas chromatography (GC). Such phases have, however, hitherto been of restricted importance in capillary GC due to the lack of phases having a viscosity high enough to ensure stationary phase film stability. Further, to utilize fully the possibilities of a methyl(phenyl)silicone capillary column, it must also possess high efficiency and a high degree of deactivation.

In this work, the preparation of soda-glass capillary columns coated within situ cured methyl(phenyl) and methyl(tolyl)-silicones is presented. Vulcanization was made possible by the introduction of some vinyl substitution in the gum to be cured: tolyl-containing gums could be cured without the presence of vinyl groups. In addition, fused silica capillary columns coated with OV-1701 were prepared.

The columns show a coating efficiency of above 80%, a thermal stability up to 320 °C and a high degree of deactivation. Their utility is demonstrated by the separation of samples containing polynuclear aromatics, antidepressants and some potent mutagens.