Ms chemstation

Fatty acid methyl esters obtained from the green coffee beans extracts were analyzed by GC–MS. It was prepared in the concentration of 9 µg/mL of the sample with 5 µg/mL of standard decanoic acid methyl ester. Samples were analyzed using GC–MS Agilent Technology 7820A GC and 5977E MSD systems equipped with auto sampler. Chromatographic separations were carried out using DB-1701 column with 30 m length, 0.25 mm internal diameter and 0.25 μm column phase thickness. Injection mode was split-less, helium was a carrier gas and 1 μL volume of the sample was injected to the inlet heated to 275 °C. An oven temperature condition was programmed as 60 °C for initial and hold for 2 min and reached up to 280 °C. The program was separated into the rate of 20 °C/min until it 200 °C and the rate of 3 °C/min up to it reaches 240 °C with zero hold time. Conditions used for the mass spectrometer were a source temperature of 230 °C, scan range 40–650 m/z, and operated in positive electron impact mode with ionization energy of 70 eV. Chromatographic and mass spectral data were processed by using the instrument built in software (MS ChemStation; Agilent Technologies, USA). For identification purposes, chromatograph library was used and its quantification was calculated by the internal standard with the relationship of relative response factors.

Small amounts (ca. 0.1–0.5 mg) of the sample were inserted into the tube of a ferromagnetic wire. The wire was placed in a glass liner and then introduced in the pyrolysis unit CPP (Pilodist, Bonn, Germany). Pyrolysis conditions were the following: Curie point temperature 500 °C, pyrolysis time 9.9 s, temperature of the pyrolysis transfer line 200 °C. The pyrolysis unit is flushed with helium, which is also the carrier gas, and is mounted directly on the split/splitless injector of a 6890N (Agilent Technologies Italia SpA, Cernusco Sul Naviglio, Italy) gas chromatograph coupled with a 5973inert (Agilent Technologies Italia SpA, Cernusco Sul Naviglio, Italy) mass spectrometer. The injector temperature was 280 °C and pyrolysate was injected in splitless or 1:20 split mode. The solvent delay was 3 min. A Restek RXI-5Sil MS column (L 30 m, i.d. 0.25, 0.25 µm film thickness) was used to separate pyrolysate with the following oven temperature program: 40 °C (2 min), 5 °C/min to 300 °C (6 min). MS transfer line temperature: 300 °C. MS conditions: linear quadrupole, EI ionization 70 eV, cycle time 2.94 scan/s, mass range m/z 50–550. Data were acquired and elaborated with MS Chemstation (Agilent Technologies Italia SpA, Cernusco Sul Naviglio, Italy). Identification of compounds was performed with the NIST08 MS library search program.