A NEW TECHNIQUE FOR STRIPPING OF POLYIMIDE COATING FROM FUSED-SILICA CAPILLARIES

A novel method for the manufacture of detection windows in polyimide-c oated fused-silica capillary columns is described. Concentrated fuming nitric acid at room temperature is utilized for stripping of the coat ing from a defined section of the capillary. The technique is particul arly suitable for columns that have a heat sensitive coating on the in ner wall or for columns that contain an immobilized hydrogel sieving-m atrix. A column holder for the simultaneous preparation of detection w indows in an array of more than 100 capillaries is also reported.