Gc ultra 1300

The procedure was performed according to Lehnhardt et al. [4 ], with minor changes. The cooled wort sample (5 mL) was transferred with 50 µL internal standard (2 mg/L p-fluorobenzaldehyde in ethanol) to a 20 mL headspace vial and stored in a cooled autosampler tray (17 °C). Extraction was performed using a CAR-PDMS-DVB fiber. First, the fiber was loaded with o-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) for 10 min at 40 °C. Afterward, the headspace of the sample was extracted for 30 min at 40 °C. Next, the fiber was injected with a 1/5-split at 270 °C into a GC (GC-Ultra 1300, Thermo Scientific Inc., Waltham, MA, USA) coupled to a single quad mass spectrometer (ISQ 7000, Thermo Scientific Inc., Waltham, MA, USA). The GC was equipped with a DB-5 column (length, 60 m; inner diameter, 0.25 mm; and film thickness, 0.25 µm; Thermo Scientific Inc., Waltham, MA, USA). The carrier gas used was helium (flow rate 1.85 mL/min). The starting temperature was held at 60 °C for 4 min, followed by heating at 5 K/min to a final temperature of 250 °C, which was maintained for 3 min. A full scan mode (m/z 35–350), with a dwell time of 0.02 s, was applied to the analysis. Each sample was analyzed in triplicate. Peak detection was performed in Xcalibur 3.1.66.10 (Thermo Scientific Inc., Waltham, MA, USA).

The procedure was performed according to Lehnhardt et al., with minor modifications [24 ]. The cooled wort sample (5 mL) and 50 µL internal standard (2 mg/L 4-fluorobenzaldehyde in ethanol) were transferred to a 20 mL headspace vial and stored in a cooled autosampler tray (17 °C). The extraction was performed using a Supelco^® 50/30 µm coating CAR-PDMS-DVB fiber from Merck (Darmstadt, Germany). First, the fiber was loaded with O-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine (PFBHA) for 10 min at 40 °C. Afterward, the headspace of the sample was extracted for 30 min at 40 °C. The fiber was injected with a 1/5-split at 270 °C into a GC (GC-Ultra 1300, Thermo Scientific Inc., Waltham, MA, USA) coupled to a single quad mass spectrometer (ISQ 7000, Thermo Scientific Inc., Waltham, MA, USA). The GC was equipped with a DB-5 column (length of 60 m; inner diameter of 0.25 mm; film thickness of 0.25 µm; Thermo Scientific Inc., Waltham, MA, USA). The carrier gas was helium (flowrate 1.85 mL/min). The starting temperature was held at 60 °C for 4 min, followed by heating at 5 K/min up to a final temperature of 250 °C, which was maintained for 3 min. A full scan mode (m/z 35–350) with a dwell time of 0.02 s was used for the analysis. Each sample was analyzed in triplicate. Peak detection was performed in Xcalibur 3.1.66.10 (Thermo Scientific Inc., Waltham, MA, USA).