In-house packing and testing of capillaries for capillary electrochromatography using simple equipment

The feasibility of producing packed capillaries for capillary electrochromatography (CEC) is evaluated. Emphasis is put on the fact that only material was used that is already available in any LC/CE orientated laboratory. An experimental set-up is developed for filling the capillaries by use of an ordinary LC pump, and frits are sintered with a glowing resistance wire, fed by a d.c. power supply. Electrochromatography was carried out in an in-house built capillary electrophoresis apparatus, without pressurizing the vials. Under these conditions, the capillaries performed well, producing up to 190,000 plates per meter. Bubble formation did not appear, on condition that the mobile phase was thoroughly helium degassed. Even at ambient temperature, electrophoresis obeyed Ohm's law up to a voltage of 30 kV, proving that Joule heating was not a major concern.