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Essential Oils of Sagę Species 189

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Fig. 4.150 MHz ^l3C NMR spectrum of S. lavandulifolia in CDCb- Expanded aliphatic

region from 15 to 30 ppm

For a relatively Iow concentration of particular components of the mix-ture and using a non-polar solvent for NMR measurements to avoid mo-lecular interactions, the Chemical shifts determined for the pure products are sufficiently stable and reproducible to be used to pinpoint the separate lines in the mixture. Analyses based on this principle have been conducted for mixtures of hydrocarbons [15], and it was shown by Casanova et al. [16] that such an approach is also possible for the analysis of essential oils. It is, therefore, necessary to collect a library of spectra of the pure compounds and to analyse a mixture by comparison of the Chemical shifts and relative intensities determined for the pure compounds with the respective lines for these compounds present in the mixtures. To collect these spectral data the spectra of the individual compounds or their simple synthetic mixtures may be recorded under much less severe conditions. It is, therefore, the objective of our work to perform such an analysis for the essential oils present in the Salvia species. Recording of representative individual spectra of compounds present in these essential oils is in progress.

Acknowledgments

The work of one author (Ł. W.) was partially supported by a PhD scholar-ship granted to him in 2008 within the framework of the 'University as a Partner of the Economy Based on Science' (UPGOW) project, subsidized by the European Social Fund (EFS) of the European Union.