Behavior of macroporous vinyl silica and silica monolithic columns in high pressure gas chromatography

•New silica based monolithic columns functionalized with vinyl groups have been used in high pressure gas chromatography (carrier gas pressure up to 60 bar).•Silica based monolithic columns showed efficiency in the range 10 000-60 000 plates per meter in high pressure gas chromatography.•Retention and selectivity can be tuned by an appropriate selection of carrier gas pressure and nature.•High speed separations of light hydrocarbons were easily performed.

80% vinyltrimethoxysilane-based hybrid silica monoliths (80-VTMS), which have been initially developed for separation in reversed-phase liquid chromatography, have been investigated in high pressure gas chromatography separations (carrier gas pressure up to 60 bar) and compared to silica monolithic columns. The behavior of both silica and 80-VTMS monolithic columns was investigated using helium, nitrogen and carbon dioxide as carrier gas. The efficiency of 80-VTMS monolithic columns was shown to vary differently than silica monolithic columns according to the temperature and the carrier gas used. Carrier gas nature was a significant parameter on the retention for both silica and vinyl columns in relation to its adsorption onto the stationary phase in such high pressure conditions. The comparison of retention and selectivity between 80-VTMS monoliths and silica was performed under helium using the logarithm of the retention factor according to the number of carbon atoms combined to Kovats indexes. The very good performances of these columns were demonstrated, allowing the separation of 8 compounds in less than 1 min.