Liquid Chromatography with Rapid Scanning Electrochemical Detection at Carbon Electrodes

Rapid scanning electrochemical detection has been Investigated with channel-type electrochemical flow cells which utilize glassy carbon and carbon fibers as working electrode materials for use with high-performance liquid chromatography or flow injection analysis. Normal pulse voltammetry, back-step corrected normal pulse voltammetry, and staircase voltammetry were investigated for their utility with rapid scanning electrochemical detection. Staircase voltammograms, which have been subtracted from the background signals, were found to give the most useful results. The voltammograms, which are acquired in flowing streams, can facilitate identification in sample unknowns. The chromatographic detection limits are approximately 3 orders of magnitude higher than those obtained with amperometric detection. However, the technique of HPLC with rapid scanning electrochemical detection provides a more complete identification than HPLC with the amperometric (dc), pulse, or dual electrode detection modes.