Characterization of Limonoids in Citrus Essential Oils by Means of Supercritical Fluid Chromatography Tandem Mass Spectrometry

The dual purpose of this research was to investigate the presence of limonoid aglycones in Citrus essential oils and to develop a rapid and reliable SFC-APCI-QqQ MS method for their characterization. In this study, 12 limonoid aglycones were tentatively identified in 11 different citrus essential oils. The developed method allowed a very fast separation in less then 7 min with a very low amount of organic solvent. Calibration curve of limonin was constructed by using a triple quad MS detector in order to quantify the limonin content in the analyzed samples. The content of limonin ranged from 0.5 (clementine essential oil) to 21.2 mg L−1 (bergamot essential oil) in the cold-pressed Citrus essential oils analyzed. Moreover, product ion scan (PIS) acquisition mode was also used for the structure elucidation of isobaric compounds. To the best of our knowledge, this is the first investigation on limonoid aglycones in Citrus essential oils.