Liquid chromatography graphite electrodes

Knecht, L.A. Guthrie, E.J. Jorgenson, J.W. On-column electrochemical detector with a single graphite fiber electrode for open-tubular liquid chromatography. Anal. Chem. 1984, 56, 479 82. 

Cataldo F. Polyynes production in a solvent-submerged electric arc between graphite electrodes. 2. Analysis by liquid chromatography. Fullerenes, Nanotubes and Carbon Nanostructures 2004, 12, 619. 

In liquid chromatography applications, with a predetermined potential at the WE and just column eluent flowing, only residual current is observed. (In chromatographic parlance this is often called standing current.) Especially when a new graphite paste electrode is first used, the residual current may be large. One or two hours of operation with the potential applied and eluent pumping may be required before the residual current decreases to a stable condition. 

Graphite electrodes used as liquid chromatography detectors are relatively free from filming effects. The amount of material normally electrolyzed is very small and the continuous washing of the surface by the flow stream appears to keep film formation at a minimum. Nevertheless, if electrochemical detectors are used in liquid chromatography, the quantities injected (especially of serotonin compounds) should not exceed several hundred nanograms. Indeed, if higher amounts are to be detected, one can use less sensitive, nonelectrochemical detector systems. 

J. Wangsa and N.D. Danielson, Electrochemical detection for high-performance liquid chromatography using a Kel-F wax-graphite electrode, J. Chromatogr. A, 1990, 514, 171-178. 

---