117828245

Low-Temperature TLC-MS ol Essentiai Dis

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(b)

Figurę 4

Densitogram (a), vkfeoacan (b) oMalned from the essentiai oll of S. trifoba, and mass spectra of separated chromatografie bands

rrtt

(1H5).

flcation of individual compounds was possible because of gas chromatographic separation of the sampies, use of a digital library of mass spectra, and comparison of the retention times of the separated essentiai oil components with those of the standard*.

With complex mbetures of compounds (for example essentiai oils), thin-layer chromatography can only provide group separation, i.e. fractionation into the less complex mixtures. This alter-native procedurę can, however, have very appreciable advan-tages if coupled with a well performing detection system. A mass spectrometer coupled with thin-layer chromatography via a TLC-MS interface can provide valuable analytical rcsults, as shown in this study.

Aftcr the Iow-temperaturę development of the chromatograms, the first step was to obtain the respective densitograms. Images of the chromatograms were also saved as videoscans. The wel) separated chromatographic bands then underwent mass spec-trometric anaJysis. The results obtained are presented in Figures 1-5. In these figures, multiple fingerprints are presented of the five sagę species, each composcd of the densitogram and four (S. lavandulifolia)_t or five (Sstaminea, S. hi ans, S. triloba, and S. nemorosa) mass spectra of the respective frac-

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Journal of Planar Chromatography 23 (2010) 4