Deactivated or undeactivated fused silica tubing.
Deactivated tubing can be used as retention gaps, guard columns or transfer lines. The standard deactivation process is a phenyl methyl deactivation. - the preferred choice for most applications due to its inertness and robustness.
Undeactivated tubing or bar fused silica is commonly used for capillary electrophoresis. It can also be used for transfer lines and other applications where inertness is not critical.