Coating capillary tubes for gas chromatography - by treating with hydrochloric acid, then filling with soln. of stationary phase

摘要

Coating or capillary tubes for use in gas-chromatography comprises first etching with HCl in a gas stream at high temp. then coating the inner wall with a moving column of a soln. of the stationary phase, followed by a mercury column and the solvent is driven off using a stream of inert gas. Etching is pref. carried out at 25-550 degrees C; esp. 300-500 degrees C.