Hp agilent 5890 gc

Flower volatile samples were analyzed by GC-MS using a HP Agilent 5890 GC and 5975 MS (Agilent Technologies) equipped with a HP-5 UI capillary column (30 m × 0.25 mm × 0.25 um, J&W). Injection was in splitless mode (250 °C, split opened after 30 s) and the oven temperature was maintained at 35 °C for the first 3 min, then increased at 10 °C min⁻¹ to 240 °C and held for 10 min. Carrier gas was helium at constant flow rate of 36 cm sec⁻¹, the ionization voltage was 70 eV, and scanning was m/z 29–300 with 2 scan/s. Compounds were tentatively identified by matching their mass spectra with those in the MS Libraries (NIST 11 and Wiley) using the Software ChemStation (D.01.02.16), and identifications were verified by injection of synthetic reference compounds. Retention indices were calculated using C8-C40 alkane calibration standard and compared to those in the libraries.

The volatile collections were analyzed with gas chromatography combined with mass spectrometry (HP Agilent 5890 GC and 5975 MS, Agilent Technologies) equipped with HP-5 UI capillary column (30 m × 0.25 mm × 0.25 μm, J&W). The injector temperature was set to 250 °C and operated in splitless mode for 30 s for solvent injection (1 μl was injected with 3 min solvent delay) and for 1 min for SPME injection. The oven temperature was maintained at 50 °C for 1 min, then increased at 10 °C min^-1 to 280 °C and held for 4 min. The flow rate of the helium was 1.0 ml min^-1. Positive electron ionisation (EI+) was used, with an electron energy level of 70 eV, 2 scans s^-1 were recorded in the range of 29–300 m/z.
Compounds were tentatively identified by matching their mass spectra with those in the MS Libraries (NIST 11 and Wiley) using ChemStation (D.01.02.16, Agilent USA). The samples were also verified by injection of synthetic standards and compared to published and calculated Kováts index (KI) values using C8-C40 alkanes calibration standards. The identification of electrophysiologically active compounds was subsequently verified by testing the synthetic standards with GC-EAD/FID. 1-octen-3-ol (98%, CAS 3391-86-4), 3-octanone (≥98%, CAS 106–68-3) and 1-hepten-3-ol (≥98%, CAS 4938-52-7) were purchased from Sigma-Aldrich and were diluted in n-hexane (HPLC grade, Merck).

The release rate of the dispensers loaded with EOs was measured on a daily basis for five consecutive days to mirror the duration of the oviposition bioassay. Three independent dispensers were measured for each EO. The headspace of EOs was sampled with SPME fibers, as described above. Prior to sampling, the vial-wick dispensers filled with 1.5 mL of EO were placed in glass vials (L: 80 mm, ID 20 mm), and 5 min before sampling the vials were sealed with aluminium foil and laboratory film (American Can, Greenwich, CT, USA). The SPME fibers were exposed to the closed headspace of the sampling vial for 5 min at room temperature and subsequently analyzed by GC-MS. The abundance of antennal active volatile compounds shared among tested EOs was monitored: 1-terpinen-4-ol, β-pinene, cis-linalool oxide, (±)-linalool and terpinolene. Before each measurement, fibers were conditioned at 250 °C in the split/splitless injector of the GC-MS (HP Agilent 5890 GC and 5975 MS, Agilent Technologies, Palo Alto, USA) in split mode for 10 min.