Process for etching and deactivating glass capillaries for chromatography.

摘要

An improved process for etching the inner surface of a glass capillary column in which ammonium bifluoride in liquid methanol is passed slowly through the capillary bore for a period of time followed by rinsing with methanol, followed by a gradually diluiting rinse mixture of methanol and water, and finally by a pure water rinse. A very fine structured etch of uniform depth is produced with no apparent air entrainment making the column suitable for all standard stationary phase coating procedures. Improved deactivation of the inner surface of the capillary column prior to coating with stationary phase is obtained by a multi-step process whereby siloxane polymer molecules are chemically bonded to the capillary inner surface. The deactivated surface is adapted to coating with an apolar liquid stationary phase.