A Comparison of Selected Analytical Approaches to the Analysis of an Essential Oil

• Published in: Flavour and fragrance journal 1997-01, Vol.12 (1), p.1-8
• Main Authors: Coleman III, W. M., Lawrence, B. M.
• Format: Article
• Language: English
• Subjects: analysis; Applied sciences; Cedar wood; Chemical industry and chemicals; dynamic headspace; essential oil; Essential oils, perfumes; Exact sciences and technology; gas chromatography; headspace; Juniperus virginiana; Juniperus virginiana L; qualitative; quantitative; solid phase microextraction; Washing products. Cosmetics and toiletries. Perfumes
• ISSN: 0882-5734; 1099-1026
• DOI: 10.1002/(SICI)1099-1026(199701)12:1<1::AID-FFJ603>3.0.CO;2-L

Four gas chromatograph‐based methods have been evaluated for their ability to provide qualitative and quantitative information on the characteristics of the components of the essential oil of Virginia cedarwood (Juniperus virginiana L.). Each method was found to possess certain strengths and limitations in providing the desired endpoints. Direct injection of solutions of the essential oil in an organic solvent provided very precise values for the percentage contribution. Solid‐phase microextraction (SPME) employing a poly(dimethylsiloxane) fibre provided information as to the distribution of major and minor volatile compounds in the headspace above the oil sample. Dynamic headspace analysis provided similar information, but both methods provided different perspectives on the constituency of the headspace. Gas‐tight sampling of the headspace provided yet another viewpoint on the components in the headspace above the cedarwood oil. The exposure time of the fibre in the SPME experiment and the sweep time of the dynamic headspace experiment were found to have a very significant impact on the resulting distribution profile of the volatile compounds. Explanations as to the causes and implications of these results on the qualitative and quantitative analysis of essential oils were provided. Therefore, the desired analytical endpoint should dictate the type of gas chromatographic approach employed. For example, if information concerning the components responsible for the aroma of an essential oil is desired, then gas‐tight sampling will provide a precise assessment of the distribution of those volatile components. On the other hand, dynamic headspace analysis and SPME will provide valuable qualitative information about all of the components of essential oils. Direct injection into a GC will provide the best quantitative information on the components of the essential oil. © 1997 by John Wiley & Sons, Ltd.