A new electrode chamber for stable performance in capillary electrophoresis

Prerequisite to running automated sequences of analyses in capillary electr ophoresis is a stable performance of the system. The products of the electr ode reaction with the running background electrolyte (BGE) may play an impo rtant role, since even the neutral products may be driven into the capillar y by electroosmosis and may severely deteriorate the stability of the basel ine. Here, a simple. inexpensive, and fast procedure is described for impro ving the stability of the performance of capillary electrophoresis using a modified vial serving as the electrode chamber for the running BGE. The mod ification is based on creating two separate rooms in the vial, one for the electrode and a second one for the capillary. These two rooms are connected by a cotton plug. When both rooms are filled with the running BGE, the ele ctrolytic connection between the electrode and the capillary is ensured; ho wever, the convective transport of the electrode reaction products into the capillary is practically eliminated.