1290 infinity 2 uhplc dad

To measure glucosinolate compounds, floret and leave samples were grinded with liquid nitrogen and transferred to 2 mL microtubes, lyophilized and stored in a −80 °C freezer. Briefly, 10 mg of lyophilized and homogenized plant material were extracted in presence of 0.02 µmol of the internal standard 4-hydroxybenzyl GS with hot 70% methanol (LC-MS grade, Th. Geyer GmbH & Co. KG, Renningen, Germany) and samples were prepared as described before [36 (link),37 (link)]. The desulfo-GS were analyzed using a 1290 Infinity II UHPLC-DAD coupled with a 6230 ToF-LC/MS (Agilent Technologies, Waldbronn, Germany) with a Poroshell 120 EC-C18 column (Agilent Technologies, Waldbronn, Germany; 100 mm × 2.1 mm, 2.7 μm). UHPLC conditions were as follows: solvent A, MilliQ water; solvent B, 100% v/v acetonitrile. The 19 min run comprised 0.2% (v/v) B (2 min), 0.2% to 19.8% (v/v) B (10 min), a 2 min hold at 19.8% (v/v) B, 19.8% B to 50% (v/v) B (1 min), a 1 min hold at 50% (v/v) B, 50% to 0.2% (v/v) B (1 min), and finally a 2 min hold at 0.2% (v/v) B. The injection volume was 5 µL, and determination was conducted at a flow rate of 0.4 mL min⁻¹ and 30 °C and a wavelength of 229 nm. The concentration of desulfo-GS was calculated by the peak area relative to the area of the internal standard.