The determination of the O2 concentration was carried out by injecting a sample of 0.25 L to the a CP-Molsieve 5 Å packed column (4 m × 0.32 mm, d.f. = 10 mm) at 60 ◦C and 100 kPa whereas a portion of 0.33 L was injected into a pora-PLOT Q column (10 m × 0.32 mm, d.f. = 10 mm) held at 75 ◦C and 200 kPa for CO2, ethylene (C2H4), acetaldehyde (C2H4O) and ethanol (C2H5OH) determinations.