Wetting Phenomena in Gas Chromatography Capillary Columns

Abstract

IN some instances poor efficiency with capillary columns has been reported, especially when glass capillaries were used. This may be due to two quite different phenomena : bad liquid-phase distribution on the smooth wall of the capillary caused by non-uniformity of radius, or non-wetting properties of the stationary phase. Giddings¹ has theoretically discussed the first reason; but experiments on it are lacking. This communication is concerned with the second point only. If the liquid phase does not spread on the wall, it coalesces into droplets: the larger these droplets the lower the efficiency. They may even come to plug the column, resulting in a sawtooth gas flow pattern. The wetting properties of the stationary phase thus appear to be very important.