Model n 5973

The most abundant bioactives contained in the essential oils have been separated and identified by GC-MS using a chromatograph (Model 6890 Chromatography) coupled with an Agilent Mass Spectrometer (Model N-5973). A capillary column (HP-5MS) with 5% methylphenylsiloxane static phase (length 30 m, internal diameter 0.25 mm, layer static thickness 0.25 μm) and ionization energy of 70 eV was used. The temperature for the analyses was first set at 60 °C and then it was increased at a rate of 3 °C up to 246 °C. The injector and detector temperatures were maintained at 250 °C, the volume of the injected sample was 1 µl and the helium carrier gas was maintained at a flow rate of 1.5 ml/min. The identification of chemical components was based on the analysis of the chromatograms obtained for each oil measuring the retention indices (RI). Data were compared with that of standards of n-alkane mixtures (C8-C20) and mass spectral data reported in computer library (Wiley-14 and NIST-14 Mass Spectral Library), and in the literature [2] .

The main bioactives contained in the essential oils have been determined by means of GC-MS, using a chromatograph (Model 6890 Chromatography) coupled with an Agilent Mass Spectrometer (Model N-5973). A capillary column (HP-5MS) with 5% Methylphenylsiloxane Static Phase (Length 30 m, Internal Diameter 0.25 mm, Layer Static Thickness 0.25 μm) and ionization energy of 70 eV was used. The temperature for the analyses was rst set at 60°C and then it was increased, at a rate of 3°C up to 246°C. The injector and detector temperatures were maintained at 250°C, the volume of the injected sample was 1 µl and the helium carrier gas was maintained at a ow rate of 1.5 ml/min. The identi cation of chemical components was based on the analysis of the chromatograms obtained for each oil, by means of the retention indices (RI) evaluation in comparison with standards of n-alkane mixtures (C8-C20) and mass spectral data of each peak by using a computer library (Wiley-14 and NIST-14 Mass Spectral Library), and comparison of the obtained results with those contained in the literature (Adams, 2007).