Hp 7890a gc

The GC-MS analysis were performed using a Hewlett-Packard HP 7890A GC coupled to a 5975C MS (Agilent Technologies, SC, USA) with a SLB-5ms column (Supelco) (30 m × 0.25 mm × 0.5 µm). Operating conditions for GC/MS analysis were as follows: helium flow, 0.8 mL/min; initial oven temperature, 40 °C (2 min), raised to 240 °C at 8 °C/min rate, held for 6 min isothermally. For all peaks retention indices were calculated to compare results obtained by GC/MS with literature data and mass spectra of eluting compounds to those of the NIST 05 library match (NIST MS Search v2.0, Toronto, Canada 2005). Retention indices were calculated for each compound using homologous series of C7–C20 n-alkanes. Mass spectra were recorded in an electron impact mode (70 eV) in a scan range of m/z 33–350 [18 (link)]. The ion source temperature was set at 200 °C. The composition of EO has been expressed as the percentage composition calculated from the chromatogram obtained on the SLB-5 column. Normalized peak area % were calculated based on the total ion chromatogram (TIC) without obtaining response factor for particular compounds.

The chemical constituents of the EOs of four species from genus Asarum were determined by combining the GC-FID and GC–MS system with the standard library and the MASSFinder library of natural compounds: The GC-MS analysis was carried out with Agilent Technologies HP7890A GC equipped with a mass spectrum detector (MSD) Agilent Technologies HP5975C, and an HP5-MS column (60 m × 0.25 mm, film thickness 0.25 µm). The GC-FID analysis was carried out with the same conditions as those for the GC-MS analysis. MassFinder 4.0 software connected to the HPCH1607, W09N08 libraries and the NIST Chemistry WebBook was used to match mass spectra and retention indices [41 (link)]. The analysis was conducted at the Chemical Analysis Lab, Institute of Natural Products Chemistry, The Vietnam Academy of Science and Technology.

An HP 7890A GC instrument combined with an HP 5975C mass selective detector (MSD) quadrupole MS instrument (Agilent Technologies, Palo Alto, CA, USA) was used for the GC–MS analysis. The capillary column utilized was HP-5MS (30 m × 0.25 mm × 0.25 μm film thickness) from Agilent technologies, and high-purity helium (purity 99.999 %) was used as carrier gas at a flow rate of 1 mL/min. The injector and ion source temperatures were set at 250 and 200 °C, respectively. Samples were injected in splitless mode. The initial GC oven temperature was 50 °C, held for 5 min, and then ramped at 3 °C/min to 210 °C, held for 3 min, and finally programmed to 230 °C at 15 °C/min. The Agilent 5975C MS was operated in the electron impact mode using ionization energy of 70 eV with an ionization source temperature of 230 °C and a quadrupole set of 150 °C. The acquisition mode was full scan (from 30 to 500 m/z), and the solvent delay time was 2.8 min.