Preparation and evaluation of an on‐line preconcentrator for capillary electrophoresis

The preparation and performance of an on‐line preconcentrator for capillary electrophoresis (CE) is described. Borosilicate glass microspheres were dry‐packed into the fused silica column terminus and sintered in place with a micro electric are developed for this application. Reversed‐phase LC packing material was slurry‐packed onto this frit, in lengths of 1‐3 mm. An additional frit of borosilicate beads behind the preconcentrator was used to fix the packed bed in place. The performance of the packed bed preconcentrator for the enhancement of UV and fluorescence detection limits was evaluated. Construction of the micro electric are device, the packing procedures, and practical applications are described.