SPME and GC-AED-Olfactometry for the detection of trace odorants in essential oils

The presence of odor active trace components in essential oils obtained from Melaleuca alternifolia have been investigated using gas chromatography atomic emission detection (GC-AED) and gas chromatography olfactometry techniques (GC-O) in combination with solid phase microextraction (SPME). Distinct qualitative and quantitative differences were found in front of the terpenoid region of both the aromagrams and the chromatograms obtained from four samples of high quality tea tree oil from different sources. These results suggest that the subtle differences observed in the aromas of the sample oils could be caused by the variability of the occurrence of these trace volatiles. The combination of SPME, GC-AED and GC-O is a useful method for studying such problems.