Gc 2010 plus apparatus

Volatile compounds of the tested beers were analysed by the gas chromatography technique coupled with flame ionizing detection (GC–FID), using a GC2010 Plus apparatus with a FID-2010 and a headspace autosampler (HS-20) (Shimadzu Corporation, Kyoto, Japan), equipped with a CP-WAX 57 CB column (50 m × 0.32 mm ID × 0.2 µm) (Agilent Technologies, Santa Clara, CA, USA). Beer samples were degassed, mixed with diatomaceous earth (1 g per 100 cm³ of beer), and filtered through a paper filter. After filtration, 10 cm³ of beer was transferred to a 20 cm³ headspace vial. Each vial was conditioned in a headspace autosampler oven set at 40 °C and equilibrated for 20 min at shaking level 2 prior to the injection of the sample into the column. The operating conditions of the chromatographic analysis are described in detail in the work published by Kawa-Rygielska et al.^{8 (link)} Six measurements were performed for each of the beers (two repetitions from three different bottles of the same beer).

GC-MS for compound identification was performed using a SHIMADZU GC-2010 Plus apparatus (Shimadzu corporation, Japan) equipped with a GCMS-QP2020 mass spectrometer coupled with an SH-Rxi-5Sil MS quartz capillary column (30 m × 0.25 mm, film thickness 0.25 μm). Helium (1.0 mL/min) was used as the carrier gas. Samples (1 μL; split ratio, 1:20) were injected into the GC (detector temperature, 280 °C), and subjected to the following temperature ramping program: initial temperature (60 °C; 2 min), followed by ramping (5 °C/min) to the final temperature (220 °C; 20 min). Qualitative analysis used electron-impact ionization (source temperature, 200 °C; interface temperature, 250 °C; ionization energy, 70 eV; scanning speed, 1000 mm/s; scanning interval, 0.50 fragments per second; mass scan range, 40–650 amu). Essential oils were identified using a digital library of mass spectral data (NIST 8.0) and literature comparisons of retention indices calibrated against a homologous series of C8-C32 n-alkanes [46 ].

The lipids from 20 mg of freeze-dried cultured cells were directly converted into methyl esters, which were analyzed via gas chromatography (GC), as described in Browse et al. (1986 (link)). The GC analysis was performed using a GC-2010 Plus apparatus (Shimadzu, France) equipped with a flame ionization detector. A BPX 70G1203 column (30 m, 0.25 mm, 0.25 μm; SGE Analytical Science, Europe) was used to characterize the fatty acid methyl esters (FAMEs). They were identified via comparison to commercial standards (CLA, CLA methyl ester, FAME37, Supelco; Sigma, Saint Louis, Missouri), and their levels were quantified using an internal standard—100 μg of commercial C17:0 (Sigma, Saint Louis, Missouri, USA).