Screening for Odorants by GC

Owing to the limitations of the isolation procedures, it has to be examined sensorially whether the odour profiles of the concentrated extract and of the starting material agree (cf discussion in [8]). In the SPME procedure this check demands an extraction of the odorants from the fibre as reported in [19]. 

After concentration of the extract by microdistillation [25] or by special procedures [26] to facilitate the identification of the odorants, an aliquot is separated by high-resolution GC and the effluent is split into a flame ionisation detector (FID) and a sniffing port [27]. The positions of the odorants in the gas chromatogram are assessed by sniffing the carrier gas as it flows from the port. This procedure is denoted GC-O. 

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