Józef Rzepa

Fingerprinting of the volatile fraction from selected thyme species by means of headspace gas chromatography with mass spectrometric detection.

The Thymus genus has a firm position in Mediterranean folk medicine and culinary tradition, and yet certain confusion is observed in its botanical taxonomy. Therefore, chemical analysis of secondary metabolites and selection of reliable chemotaxonomic markers can prove helpful. In this study, the volatile fraction derived from 20 different thyme specimens was analyzed by means of headspace GC with MS detection. From the obtained chromatographic fingerprints, the diversity of the volatile fraction originating from the different thyme species clearly emerged. Identification of volatile components was based on a software library of mass spectra. There was only one common component derived from all 20 investigated thyme species, i.e., ß-linalool. For three different Thymus species, a comparison was made of the performance of the headspace extraction and hydrodistillation. Characteristic differences in composition of the volatile fraction obtained with use of these two techniques were discussed. Finally, the obtained chromatographic fingerprints of the volatile fraction were analyzed by means of a chemometric approach (principal component analysis), in order to trace similarities in their chemical composition.

A Comparison of Methodical Approaches to Fingerprinting of the Volatile Fraction from Winter Savory (Satureja montana)

It was the aim of this study to compare the efficiency of the different essential oil extraction methods upon the two winter savory (Satureja montana) samples of different origin. The compared techniques were the headspace gas chromatography with mass spectrometric detection (HS-GC/MS) run at the two different headspace temperatures (i.e., at 80 and 100°C) and the three different steam distillation techniques preceding the GC/MS analysis. HS-GC/MS is considered as the technique of the first choice, and the compared steam distillation techniques are recommended, respectively, by Polish Pharmacopoeia, European Pharmacopoeia, and the Polish Patent. Adequate conclusions were drawn as to the advantage of HS-GC/MS (not having the pharmacopoeial recommendation) over the different steam distillation techniques and the drawbacks of each individual analytical procedure were discussed.