5975c network mass selective detector

Terpenoid detection was analyzed using an Agilent 7890A gas chromatograph coupled to an Agilent 5975C Network Mass Selective Detector (MS, insert XL MSD with triple-axis detector). Chromatographic column: HP-5MS column (30 m × 0.25 mm × 0.25 μm; J&W Scientific, Folsom, CA, USA); Carrier gas: He (purity ≥ 99.999%); Injection port temperature: 280 °C; Injection method: Splitless injection; Injection volume: 1 µL. Program temperature rise: the initial temperature is 60 °C for 2 min, the temperature is increased at 20 °C/min to 220 °C for 1 min, the temperature is increased at 5 °C.min⁻¹ to 250 °C for 1 min, and finally the temperature is increased at 20 °C.min⁻¹ to 290 °C for 7.5 min.
Ion source: EI; ion source temperature: 230 °C; ion energy mode: use tuning setting; ion energy (eV): 70; detector setting: use gain factor; solvent delay: 5 min; mass scan range: 30~500.

Samples without derivatization were diluted to 2% in heptanol, using 1 µL of each sample for the analysis, and each sample was analyzed in triplicate. GC-MS analysis was performed using a 7890A Network GC System coupled to a 5975C Network mass selective detector (MSD) and 7683B autosampler (Agilent Technologies, Wilmington, DE, USA). The separation was performed using an HP-5MS capillary column (0.25 mm i.d. × 30 m, 0.25 µm film thickness) (J&W, Folsom, CA, USA). The injector was operated in splitless mode at 300 °C, with a flow of 0.8 mL/min, and the oven temperature was programmed to 40 °C for 3 min, and then heated at 3 °C/min to 300 °C with a holding time of 5 min at the final temperature. The MSD was operated at 70 eV; the ion source was set at 150 °C and the transfer line at 300 °C. VOCs were identified by interpreting their mass spectra fragmentation in the mass range of 15 to 800 atomic mass units. The software MSD ChemStation (Agilent) was used for data recording. The compounds were identified by comparing the obtained mass spectra with those of reference compounds from the National Institute of Standards and Technology (NIST11) and Wiley 9th. The identities of the compounds were confirmed by the Kovats retention index calculated for each peak with reference to the n-alkane standards (C7–C38) running under the same conditions.