Chemical Composition of the Essential Oil of Geum rhodopeum

were collected in June 2010 at Prestojceva mahala (Cemernik Mountain-42 44 45.43N, 22 18 40.01 E, Elev. 1339 m). The plant material was authenticated by one of the authors (V. N. Randjelovic). A voucherspecimen, with the accession number 16680, is deposited at the Herbarium of the Department of Botany, Faculty of Biology,University of Belgrade – Herbarium Code BEOU.Oil was obtained from air-dried aerial parts of the plant with 0.01% (w/w) yield by hydrodistillation for 4 h using aClevenger-type apparatus. The oil analyses were performed simultaneously by gas chromatography (GC) and gaschromatography-mass spectrometry (GC-MS) systems. The GC analysis of the oils was carried out on a GC HP-5890 IIapparatus equipped with a split-splitless injector, an HP-5MS capillary column (30 m 0.25 mm, 0.25 m film thickness) withhelium as the carrier gas (1 mL/min), and FID. Operating conditions: injector temperature 250 C and interface temperature280 C, temperature program from 50 C (3 min) to 250 C at a rate of 3 C/min. Volume injected, 1 L of the oil in ether (0.5%).GC/MS analyses, under the same gas-chromatograph conditions, were performed on an Agilent Technologies apparatus,Model GS 6890N coupled with a mass selective detector MSD 5975C. The MS operating parameters were as follows: ionizationpotential 70 eV; ion source temperature 250 C; quadrapole 150 C, solvent delay 3.0 min, mass range 50–550 amu, Em voltage1435 V.Identification of the compounds was based on comparison of Kovats retention indexes (applying calibrated automatedmass spectral deconvolution and identification system software (AMDIS ver. 2.64) in combination with selective ion analysis(SIA) resolution method [11]), comparison with the spectral data from the available literature [12], and comparison of theirmass spectra to those from Wiley 275 and NIST/NBS libraries using various search engines. Relative retention indexes (RRI)were obtained by co-injection with an aliphatic C