GCMSolfactometry

GC-MS olfactometry, often abbreviated as GC-MS/O, is an analytical technique that combines gas chromatography with olfactory assessment and mass spectrometric detection to identify and characterize odor-active compounds in complex samples. The method splits the effluent of a GC column between an olfactometer, where trained panelists perceive and describe odors, and a mass spectrometer, which provides chemical identification and structural information.

In a typical workflow, samples such as food, beverages, fragrances, or environmental matrices are prepared and injected into the GC. As separated compounds elute, a portion of the stream is directed to the sniffing port for human evaluation, while the remainder goes to the MS for spectral analysis. Panelists record odor descriptors, intensity, and perceived onset relative to retention time. The odor data are correlated with the GC retention times and MS data to pinpoint which compounds contribute to the overall aroma. Retention indices and MS library matches aid in identifying the odor-active molecules, and odor activity values can be estimated by combining concentration with perceived intensity.

Key advantages of GC-MS olfactometry include the ability to link sensory perception directly to specific chemical compounds, enabling more precise aroma profiling and prioritization of target molecules for quantification or sensory optimization. The technique is widely used in flavor and fragrance research, quality control, and environmental odor assessments.

Limitations include the subjectivity and variability of human assessors, the need for well-trained panels, and the complexity and cost of the instrumentation.