Fast-scan a.c. voltammetry for better resolution of chromatographically overlapping peaks

A fast-scan phase-sensitive a.c. voltammetric detector for high-performance liquid chromatography is described. The mercury drop electrode is periodically polarized over a certain potential range and only the maximum current value of each scan is plotted. The technique makes it possible to resolve chromatographically overlapping peaks provided that the voltammetric peak potentials of the corresponding compounds differ enough. Practical examples of application of the technique to nitro compounds are reported, and limitations are discussed.