Conventional GC columns
Conventional GC column cover the range of internal diameters including 0.15mm, 0.2mm, 0.25mm and 0.32mm.
Similar to all GC columns, selecting the column is a choice between optimising selectivity, speed of analysis, resolution, capacity and other factors.
In general terms, 0.15, 0.20 or 0.25mm id columns can be used where higher column efficiencies are needed. Ultimate efficiencies are possible using narrower bore Fast GC columns of 0.05 and 0.1mm id.
0.15 and 0.20mm id columns are especially well suited for GC/MS systems with low pump rates are in use.
Thicker film columns tend to be used for more volatile species. If high capacity is required as well, a thick film 0.32m id column would be a better choice than a 0.20mm thin film column for example. A 0.32mm id columns will often give better resolution of earlier eluting solutes for splitless injections or large injection volumes (>2 μL) than 0.25 mm id columns.
All available phases are offered in the above diameters. These range from apolar DR-1 and similar phases through mid-polar (based on 0-100 scale) ethylene glycol based DR-wax to high polarity cyano-rich silicone phases (DR-10).