Hp 5 ms 5 phenyl methyl poly siloxane capillary column

MLE was dissolved using 3 mL ethyl acetate and 1 mL was transferred to GC vial for GC/MS analysis after evaporation. The investigation of various substances of MLE that were present in modest quantities was performed using gas chromatography-mass spectrometry. The components were identified by comparing their mass spectra and retention times to those of the authentic compounds, as well as by computer matching with the NIST and WILEY libraries and by comparing the fragmentation pattern of the mass spectral data to those reported in the literature. The analysis was performed with a GC (Agilent Technologies 7890A, Poway, CA) interfaced with a mass-selective detector (MSD, Agilent 7000, Poway, CA) equipped with a polar Agilent HP-5 ms (5%-phenyl methyl poly siloxane) capillary column (30 m 0.25 mm in diameter and 0.25 m film thickness). Helium was used as the carrier gas, with a linear velocity of 1 mL/min. The injector and detector temperatures were 200 °C and 250 °C, respectively. Volume injected was 1 μL of the sample. The MS operating parameters were as follows: ionization potential 70 eV, interface temperature 250 °C, and acquisition mass range 50–800²³ .

GC–MS analyses were carried out with an Agilent Technologies (Palo Alto, CA, USA) gas chromatograph model 7890 A equipped with a mass-selective detector (MSD) model 5975 C (Agilent Technologies, Palo Alto, CA, USA) and an HP-5MS 5% phenyl-methylpolysiloxane capillary column (30 m × 0.25 mm, 0.25 μm film thickness). In brief, the injector and detector temperatures were 250 °C and 300 °C, respectively; the column temperature was held at 70 °C for 2 min, was then increased from 70 to 200 °C at 3 °C/min, and was finally held at 200 °C for 18 min; 1.0 μL of the sample was injected using split mode (split ratio 1:50). Helium was used as a carrier gas (1.0 mL/min). The MSD (EI mode) was operated at 70 eV, and the scan range was set to 30–350 amu. Identification of volatile constituents was based on the comparison of their retention indices (RIs), determined relative to the retention times of a homologous series of n-alkanes (C₉–C₂₅), with those reported in the literature, and their mass spectra with those of authentic compounds available in our laboratories or those listed in NIST 17 (D-Gaithersburg, MD, USA) and Wiley W9N08 (Wiley, New York, NY, USA). Relative concentrations of components were calculated by the area normalization method without considering response factors.

Gas chromatography−mass spectrometry (GC-MS) analyses were conducted on an Agilent Technologies 7890B GC system equipped with a 5977B GC/MSD quadrupole mass spectrometer (Agilent Technologies, Santa Clara, CA, USA), a 7693A autosampler, and a split/split-less inlet. The chromatographic separation was performed using a HP-5ms (5% phenyl-methylpolysiloxane) capillary column of dimensions 30 m × 0.25 mm I.D. × 0.25 μm film thickness (Agilent Technologies, Santa Clara, CA, USA). The chromatographic conditions were: oven temperature program, 40 °C (hold 2 min), then heated at 3 °C min⁻¹ to 270 °C; injector temperature, 300 °C; carrier gas, helium (purity of 99.999%) at a flow rate of 1.0 mL min⁻¹ (24.02 cm s⁻¹); injection volume, 1 µL, and using a split ratio of 20:1. The MS was operated in electron ionization (EI) mode at 70 eV, transfer line temperature of 300 °C, ion source temperature of 230 °C, mass scan range of 45–500 Da, and solvent delay time of 2.6 min.