Coupled Gas Liquid – Thin Layer Chromatography: Simultaneous Determination of Piperitone and Piperitone Oxide in Essential Oils

Gas liquid and thin layer chromatography have been combined into a single microphysicochemical technique. The resolution of two terpenoids found in nature—piperitone and piperitone oxide—is described to illustrate the scope of the novel method of analysis. Occurrence of the epoxide in Mentha arvensis (Japanese mint), Mentha piperita (Mitcham peppermint), Eucalyptus dives Schauer, "Type" ("broad-leaved peppermint"), and Eucalyptus numerosa Maiden, var. "A" is reported for the first time. Its presence in these species should prove of biochemical as well as taxonomic interest.