Agilent 7820 gc with 5975 msd

Volatile compounds were extracted using SPME followed by Agilent 7820 GC with 5975 MSD (Agilent Technologies Inc.) equipped with ZB-5ms column (30 m length × 0.25 mm i.d. × 0.25 µm film thickness; Phenomenex Inc.). The sample preparation and SPME-GC-MS method were modified from the method used by White et al. (2013) . Sample introduction was accomplished using a CTC Analytics CombiPal Autosampler (Zwingen, Switzerland). Vials were equilibrated for 25 min at 35°C with 4 s pulsed 250 rpm agitation. A 3 phase 50/30 µm DVB/ CAR/PDMS (Supelco) fiber was used for all analysis. The SPME fiber was exposed to the samples for 40 min at depth 3.1 cm. The fiber was retracted and injected at 5.0 cm in the GC inlet for 5 min. Samples were held at 5°C before fiber exposure. The GC oven temperature was 40°C for 3 min with gradual increases of 10°C/ min to 90°C, 5°C/min to 200°C held for 10 min, and 20°C/min to 250°C held for 5 min. Inlet temperature was 250°C and set to splitless mode. A constant flow rate of 1 mL/min (helium) was maintained throughout. The MS transfer line was maintained at 250°C with the quad at 150°C and source at 250°C. Selective ion mode for ions 98 (FA) and 128 (2-methyl-3-heptanone) was performed to identify compounds of interest. Furfuryl alcohol was quantified by relative abundance using 2-methyl-3-heptanone as an internal standard.

Volatile compounds were extracted from pure vitamin concentrates by headspace solid-phase microextraction (SPME). All injections were made on an Agilent 7820 GC with 5975 MSD (Agilent Technologies Inc., Santa Clara, CA) with a ZB-5MS column (Zb-5ms 30 m length × 0.25 mm i.d. × 0.25 µm film thickness; Phenomenex, Torrance, CA). Sample introduction was accomplished using a CTC Analytics CombiPal Autosampler (Zwingen, Switzerland). Five milliliters of vitamin concentrate and 20 µL of internal standard solution (2-methyl-3-heptanone in ether at 81 mg/kg; Sigma Aldrich) were added to 20-mL SPME vials (Microliter Analytical, Suwanee, GA) in triplicate. Vials were equilibrated for 25 min at 40°C with 4-s pulses of 250-rpm agitation. A 1-cm SPME fiber (divinylbenzene/carboxen/polydimethylsiloxane; Supelco, Bellefonte, PA) was used for all analyses. The SPME fiber was exposed to the samples for 40 min at 3.1 cm depth. The fiber was retracted and injected at 5.0 cm in the GC inlet for 5 min. Scanning from 30 to 350 m/z was performed to identify compounds of interest. Each lot of each vitamin concentrate was evaluated in triplicate.