Abstract: An on-column, etched fused-silica porous junction interface was designed and fabricated, and an integrated two-dimensional separation platform involving on-line coupling of capillary isoelectric focusing (CIEF) with capillary electrophoresis (CE) was constructed by the interface. The primary advantages of this novel porous junction interface over previous designs are no dead volume, simplicity, ruggedness and convenience of column switching. This interface is particularly well suited for on-line coupling of CE-based multiple dimensional separation system. The feasibility and performance of the 2D CIEF-CE system constructed by such an etched porous junction were evaluated by the separation of soluble extracts of an antler. The results indicated that the total separation time was less than 1 h, and the 2D CE separation system was found to increase the resolving power and overall peak capacity over single dimension mode.

Key words: capillary electrophoresis, two-dimensional separation system , etched fused-silica porous junction interface