Selected volatile components were analyzed by gas chromatography (GC) coupled to a combustion-isotope ratio mass spectrometer to assess their Î´13C values in authentic citrus leaf oils. In particular were analyzed lemon, mandarin and bitter orange petitgrain oils industrially produced by a local factory. All the samples were then analyzed by gas chromatography mass spectrometry and gas chromatography-flame ionization detection and enantio-GC for the quality assessment of each petitgrain. These values were then compared and genuineness of each sample was defined based on all the different parameters detected. The results show good agreement between the different analytical approaches. In addition in this article are reported for the first time the Î´13C values relative to genuine bitter orange petitgrain oil, useful for the quality assessment of this niche product of great economical importance.