Large-volume wall-jet cells as electrochemical detectors for high-performance liquid chromatography

The wall-jet electrode is an attractive configuration for electrochemical detectors for high-performance liquid chromatography (h.p.l.c.) on account of its high convective mass-transfer characteristics. Another important, though less recognized, feature is its small effective cell volume, which is shown to be almost independent of the geometric cell volume. The effective volume is less than the volume of the hydrodynamic boundary layer, or only a few microlitres. The practical use of the wall-jet detector in both normal-phase and reverse-phase h.p.l.c. is discussed with particular reference to the distance between the jet and the electrode. A new cell design is proposed.