| MS Description
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<Flavonoid-targeted profiling by LC‒PDA … <Flavonoid-targeted profiling by LC‒PDA‒MS>
This analysis was performed as described previously (Tohge et al., 2005a), except that the column was changed to Atlantis T3 (5µm, 4.6 mm×150 mm; Waters, http://www.waters.com/).
Reference:
Tohge, T., Nishiyama, Y., Hirai, M.Y. et al. (2005a) Functional genomics by integrated analysis of metabolome and transcriptome of Arabidopsis plants over-expressing an MYB transcription factor. Plant J. 42, 218–235.
<Untargeted profiling by LC‒QTOF‒MS>
Frozen or freeze-dried samples were extracted with 5 or 50 μl of 80% methanol (MeOH) containing 2.5 μm lidocaine per milligram fresh or dry weight, respectively, which was an internal standard for positive mode analysis, using a mixer mill (MM300; Retsch, http://www.retsch.com/) together with one zirconia bead per tube for 10 min at 20 Hz. After centrifugation at 15 000 g for 10 min and filtration using an Oasis HLB 96-well μElution Plate (Waters), the extracts (1 μl) were analyzed by LC‒QTOF‒MS (LC, Waters Acquity UPLC system; MS, Waters Xevo G2 Q-Tof). The analytical conditions were as follows. For LC: column, Acquity bridged ethyl hybrid (BEH) C18 (1.7 μm, 2.1 mm × 100 mm, Waters); solvent system, solvent A (water including 0.1% formic acid) and solvent B (acetonitrile including 0.1% formic acid); gradient program, 99.5% A/0.5% B at 0 min, 99.5% A/0.5% B at 0.1 min, 20% A/80% B at 10 min, 0.5% A/99.5% B at 10.1 min, 0.5% A/99.5% B at 12.0 min, 99.5% A/0.5% B at 12.1 min, and 99.5% A/0.5% B at 15.0 min; flow rate, 0.3 ml min−1; column temperature, 40°C. For MS: capillary voltage, +3.0 keV, cone voltage, 25.0 V; source temperature, 120°C; desolvation temperature, 450°C; cone gas flow, 50 L h−1; desolvation gas flow, 800 L h−1; collision energy, 6 V; mass range, m/z 100–1500; scan duration, 0.1 sec; interscan delay, 0.014 sec; mode, centroid; polarity, positive; lockspray (leucine enkephalin); scan duration, 1.0 sec; interscan delay, 0.1 sec. ration, 1.0 sec; interscan delay, 0.1 sec.
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