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Vapor Distillation of Essentials Oils from the Salvia Species

Dried plant materiał (50 g) was placed in a round-bottomed fiask and 400 mL water was added. Vapor distillation was conducted for 3 h with use of a Deryng apparatus. The procedurę is described in Polish Pharmacopoeia VI [10] and it has proved morę efFective than traditional solvent extraction and accelerated solvent extraction (ASE) for this particular purpose, as documented in our comparative study [11]. Yields of the distilled essential oils in the S. lavandulifolia samples were ca. 0.5 mL per 50 g dried plant materiał (ca. 1%, v/w).

Low-Temperature Thin-Layer Chromatography with Densitometric Detection

(LT TLC-Densitometry)

Thin-layer chromatographic separations were performed on commercial glass plates (20 cm x 20 cm) precoated with 0.25mm layers of silica gel 60 F254 (Merck KGaA, Darmstadt, Germany; cat. no. 1.05715). Essential oil samples originating from vapor distillation were spotted onto the thin layer in the 5-pL aliquot of undiluted sample, using an AS 30 model autosampler (Desaga, Heidelberg, Germany). Development of the chromatograms was carried out at -10±0.5°C (inside the refrigerator), for a distance of 15 cm in the one-dimensional development modę, using the binary mobile phase toluene - ethyl acetate (95:5; v/v) [12]. Chromatograms were developed in sandwich DS chambers (Chromdes, Lublin, Poland), previously saturated with mobile phase vapor for 15 min.

The developed chromatograms were dried for 3 h at ambient air and eventually evaluated by means of densitometry. Acquisition of the densitograms was carried out with a Desaga CD 60 model densitometer equipped with Windows compatible ProQuant software (Desaga). Concentration profiles of the development lanes for the sagę samples were recorded in reflected ultraviolet (UV) light fforn a deuterium lamp at 340 nm. The dimensions of the rectangular light beam were 2.0 mm ^x 0.1 mm. Each TLC analysis was performed in triplicate. Then the developed and scanned chromatographic plates were carefully wrapped in plastic foil and placed in refrigerator prior to the commencement of the next experimentai step, which was either direct analysis of the separated chromatographic bands with use of mass spectrometer (LT TLC-MS), or an indirect analysis of these bands by further separating them with use of high-performance liquid chromatographic system followed by mass spectrometric detection (LT TLC-LC-MS). Placement of the chromatograms in refrigerator