Detection of odor-active compounds by gas chromatography-olfactometry (GC-O)

Trained employee smells a heated outlet of the gas chromatograph

Gas chromatography (GC) coupled to flame ionization detection (FID) or mass spectrometry (MS) is an effective tool for the analysis of volatile compounds within complex sample extracts. When targeting odor-active compounds, the system is combined with an olfactory detection port (ODP), as in GC-olfactometry (GC-O), which enables these to be specifically identified and characterized. This is achieved through our trained sensory experts, who smell and record the odor impressions of the compounds as they elute from the chromatographic column and enter the ODP. By comparing odor impressions and various analytical data, such as retention time (index) and mass spectrum, with equivalent attributes of reference compounds, the odor-active (aroma) compounds within a sample can be identified. When further combined with aroma extract dilution analysis (AEDA), the relative potencies of constituent odorants can be ascertained. Our comprehensive two-dimensional GC-GC-MS/O systems are implemented when a higher degree of separation is needed, or when sample enrichment is required due to exceedingly low concentrations.