Agilent 1290 infinity lc pump

Glucosinolates were detected as previously described (Glauser et al., 2012 (link)). The 18-day-old Arabidopsis leaves were immediately frozen in liquid nitrogen after harvest and lyophilized to dryness for 24 h. The dry samples (10–20 mg) were extracted with 2 ml of 70% methanol (v/v), with 0.1 μmol internal standard (sinigrin) and then incubated at 80°C for 15 min. The samples were centrifuged after cooling. The supernatants were concentrated in a vacuum to a final volume of 250 μl and filtered using a syringe filter before being used for liquid chromatograph-mass spectrometer (LC-MS) analysis. The prepared samples (5 μl) were analyzed using an Agilent 1290 Infinity LC pump (Agilent, Santa Clara, CA, United States) and by 6125 single quadrupole mass spectrometry. The analysis conditions were as follows: HPLC: column: ACQUITY UPLC CSH C18 (pore size 1.7 μm, length 2.1 × 100 mm); solvent system: acetonitrile (0.1% formic acid), water (0.1% formic acid); gradient program, 0 min: 2:98 v/v, 6 min: 45:55 v/v, 6.5 min: 100:0 v/v, 8.5 min: 100:0 v/v; flow rate, 0.4 ml/min; temperature, 25°C. Mass spectrometry detection: capillary voltage, 3,000 V; air temperature, 350°C; dry gas flow rate, 12 L/min. LC-MS based metabolomics was performed using the negative ion mode (Mz 100–1,000).