Hp 6890

The volatile compounds of C. cyminum essential oil was identified using gas chromatograph (HP6890, Agilent Technologies) interfaced to a mass-selective detector (HP model 5973, Agilent Technologies). The columns used was a HP-5MS (5% phenyl polymethylsiloxane) capillary column (30 m × 0.25 mm × 0.25 μm) (Agilent Technologies). Purified helium gas was used as the carrier gas. The temperature program was initially set at 60°C and increased to 220°C at a rate of 3°C/min. Injector temperature was set at 250°C while detector temperature was set at 280°C, respectively. The ionization energy was 70 eV and molecular mass were scanned ranging from 30–300 AMU. The voltage of electron multiplier was programed at 1150 V. The temperature of ion source was set at 230°C while quadrupole temperature was set at 250°C. The volatile compounds were identified by comparing their retention indices relatively to C₈-C₁₇ n-alkanes, with those obtained from Adams databases [27 ]. Moreover, their spectra were also compared to those found in the Wiley7N, NIST98 Mass Spectral Library. The quantitation of volatile compounds was performed using gas chromatograph (HP 6890, Agilent Technologies) equipped with a flame ionization detector. The volatile components were reported as the relative peak area percentage.

Volatile carboxylic acids were analyzed in the 120 d ripened cheeses using a Hewlett Packard HP 6890 gas chromatograph (Agilent Technologies, Basel, Switzerland) as described by Fröhlich-Wyder et al. (2013) (link).

Chemicals and solvents were purchased from suppliers and used without further purification. ¹H and ¹³C NMR spectra were recorded with a 400 MHz spectrometer at rt in CDCl₃ solution (unless otherwise specified), using TMS as an internal standard for ¹H and CDCl₃ for ¹³C; chemical shifts δ are expressed in ppm relative to TMS. GC-MS analyses were performed on an Agilent HP 6890 gaschromatograph equipped with a HP-5MS column (30 m × 0.25mm × 0.25 μm), with t_inj = 250°C, injecting 1 μL of solution, and using He as a carrier gas (1.0 mL·min⁻¹). Method: 60°C (1 min)/6°C/min/150°C (1 min)/12°C/min/280°C (5 min). Determination of enantiomeric excess of products 13–24 was performed by chiral GC analyses on a DANI HT 86.10 gas-chromatograph equipped with a Varian Chirasil-DEX-CB (25 m × 0.25 mm) column and a flame ionization detector, with t_inj = 250°C and t_det = 250°C, injecting 1 μL of solution and using H₂ as a carrier gas (1.5 mL·min⁻¹). (see Supporting Information for details).