Qualitative and quantitative analysis of vetiver essential oils by comprehensive two-dimensional gas chromatography and comprehensive two-dimensional gas chromatography/mass spectrometry

• GC × GC techniques applied to the analysis of sesquiterpene derivatives.
• Comparative analysis of vetiver oils of different origins by means of GC × GC–MS.
• Quantitation of vetiver oil constituents by internal calibration using GC × GC-FID.
• Influence of the injection mode on the determined chemical composition.

Vetiver essential oils (VEO) are important raw ingredients used in perfume industry, entering the formula of numerous modern fragrances. Vetiver oils are considered to be among the most complex essential oils, resulting most of the time in highly coeluted chromatograms whatever the analytical technique. In this context, conventional gas chromatography has failed to provide a routine tool for the accurate qualitative and quantitative analysis of their constituents. Applying comprehensive two-dimensional gas chromatography techniques (GC × GC-FID/MS) afforded the mean to separate efficiently vetiver oil constituents in order to identify them in a more reliable way. Moreover, this is the first time that a complete true quantitation of each constituent is carried out on such complex oils by means of internal calibration. Finally, we have studied the influence of the injection mode on the determined chemical composition, and showed that several alcohols underwent dehydration under defined chromatographic conditions (splitless mode) usually recommended for quantitation purposes.