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Low-Temperature TLC-MS of Essential Oils

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Figurę 2

Densit ogram (a), vldeoscan (b) obtained from the essenttal oii of S. staminea, and mass spectra of aeperated chromatographlc banda

(1H5).

plant materiał (ca. 0.1% v/w). 'rhus the firrt two sagę species (5. lavandulifolia and S. trilobd) can be regardcd as rich in cssential oils whereas the other three species (Shians, S. staminea; and S. nemorosa) yielded ca a factor of ten less cssential oil and, con-sequently, cannot be regarded as particularly oily species.

For TLC analysis 0.05 mL cssential oils from S. hians, S. sta-minea, and S. nemorosa were diluted to l mL with n-hexane (volumes of undiluted samples did not allow a sufficient number of analytical replicates). Essential oils from S. lavandulifolia and S. triloba werc used undiluted.

2.3 Thln-Layer Chromstography (TLC)

Thin-layer chromatography was performed on 10 cm * 20 cm glass plates precoatcd with 0.25-mm layers of silica gel 60 F,_M

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(Merck, Darmstadt, Germany; #1.05715). Essential oil samples werc applied to the layers, either as 15-pL volumes of w-hexane Solutions ofS. hians, S. staminea, and S. nemorosa essential oils or as 5-pL volumes of undiluted S lavandulifolia and S. triloba essential oils, by means of an AS 30 sample applicator (Desaga, Heidelberg, Germany). One-dimensional developmcnt of the chromatograms, to a distancc of 15 cm, at-10 i 0.5°C (inside a refrigerator), with toluenc-cthyl acetate 95:5 (v/v) as binary mobile phase [4|, was performed in DS sandwich chambers (Chromdcs, Lublin, Poland) prcviously saturated w^fith mobile phase vapor for 15 min. The chromatograms were dried for 3 h in ambient air then scanned with a Desaga CD 60 densito-meter equipped with Windows-compatible ProQuant st)ftw^fare (Desaga). Concentration profiles of the development lanes for the sagę samples were rccorded in reflectcd ultravio!et (UV)

Journal of Planar Chromatography 23 (2010)4