Multidimensional gas chromatography hyphenated to mass spectrometry and olfactometry for the volatile analysis of citrus hybrid peel extract

• Detailed chemical characterization of the peel extract of limequat.
• Several coelutions present in the GC/MS were resolved using MDGC–MS.
• MDGC–MS on-line enrichment, has been useful for the identification of trace components.
• Es-MDGC–MS has been used to investigate the enantiomeric distribution.
• Es-MDGC–MS/O has been used to characterize the sensorial properties of each enantiomer.

In this work, the volatile composition of the peel extract of limequat, a natural citrus hybrid, was investigated by using both conventional (gas chromatography–mass spectrometry [GC–MS], deconvolution) and more advanced (multidimensional GC–MS/olfactometry [MDGC–MS/O] and enantioselective [Es]-MDGC–MS/O) analytical techniques. Although the GC–MS analysis identified most of the components, some peaks remained unidentified. These unknown peaks were elucidated by deconvolution processing and using a selectable one-dimensional or two-dimensional GC–MS system equipped with an olfactometry port. The MDGC results, with both polar and chiral second dimensions, hyphenated to mass spectrometry and olfactometry, proved to be particularly useful for the identification and chiral characterization of coeluted trace compounds. In particular, the application of the Es-MDGC–MS/O configurations was used to confirm, by on-line enrichment, the presence of cis-δ-jasminlactone. This technique was fundamental for the reliable identification and exact determination of the enantiomeric distribution of this chiral compound, as well as for the sensorial evaluation of each enantiomer at the sniffing port.