Characterization of volatile compounds in Mentha spicata L. dried leaves

Gas chromatography-mass spectrometry (GC-MS) is one of the most common techniques used to measure and to characterize volatile organic compounds (VOCs). At the same time, the proton transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) represents a recent innovative tool that allows the on-line monitoring of VOCs providing the whole mass spectra with short response time, high mass resolution and without sample preparation. We reported as major constituents of headspace in spearmint dried leaves the monoterpenes carvone, followed by dihydrocarvone, limonene and 1,8-cineole (eucalyptol) although other monoterpenes such as a-pinene, 3-carene, terpineol and neodihydrocarveol, alcohols (3-octanol, 1-octen-3-ol and 3-methyl-1-butanol), esters and ketones (3-octanone) were detected in low concentrations. In this study, the analytical GC-MS and PTR-ToF-MS techniques allowed to characterize the entire volatile profile of the sample bypassing the limitations of each tool.