Above is an example of a CPS-polished 180u OD 100u ID glass capillary.
Unpolished capillaries have irregular jagged ends with loose polyimide flapping about. 360u OD hand cut
Put glass ends like this in a fitting and expect them to continue to degrade with pressure and solvent. Typically several ul’s of dead volume form at every unfinished capillary end, reducing chromatographic efficiency dramatically. Broken glass and dissolving polyimide will travel downstream and clog the column and other fittings. Really, it is kind of amazing anybody can do anything good with hand cut glass capillaries.
The CPS polishes the ends to near perfection, imparting many benefits to the system.
Finished ends leave no dead volume in the fitting, improving chromatographic performance, extending glass capillary component service lifetime, reducing sample-to-sample carry over. This technique allows you to approach theoretical maximum chromatographic efficiency in just a few quick steps.