| MS Description
|
Fresh samples were extracted with 5 μl of … Fresh samples were extracted with 5 μl of 80% MeOH containing 2.5 µM lidocaine and 10-camphor sulfonic acid per mg fresh weight using a mixer mill with zirconium beads for 7 min at 18 Hz and 4 °C. After centrifugation for 10 min, the supernatant was filtered using an HLB μElution plate (Waters). The extracts (1 μl) were analyzed using LC-QTOF-MS (LC, Waters Acquity UPLC system; MS, Waters Xevo G2 Q-Tof). Analytical conditions were as follows: 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% (v/v) formic acid] and solvent B [acetonitrile including 0.1% (v/v) formic acid]; gradient program, 90% A/10% B at 0 min, 90% A/10% B at 0.1 min, 80% A/20% B at 25 min, 0% A/100% B at 25.1 min, 0% A/100% B at 27.5 min, 90% A/10% B at 27.6 min and 90% A/10% B at 30.0 min; flow rate, 0.3 ml/min; column temperature, 40 °C; photodiode array, 200–500 nm; flavonoid detection, 320 nm; MS detection: capillary voltage, + 3.0 keV, cone voltage, 25.0 V, source temperature, 120 °C, desolvation temperature, 450 °C, cone gas flow, 50 l/h; desolvation gas flow, 800 l/h; collision energy, 6 V; mass range, m/z 50‒2000; scan duration, 1.0 s; inter-scan delay, 0.014 s; data acquisition, centroid mode; polarity, positive; Lockspray (leucine enkephalin): scan duration, 1.0 s; inter-scan delay, 0.1 s. MS/MS data were acquired in the ramp mode in the following analytical conditions: (1) MS: mass range, m/z 50–1500; scan duration, 1.0 s; inter-scan delay, 0.014 s; data acquisition, centroid mode; and (2) MS/MS: mass range, m/z 50–1500; scan duration, 0.1 s; inter-scan delay, 0.014 s; data acquisition, centroid mode; collision energy, ramped from 10 to 50 V. In this mode, MS/MS spectra of the top 10 ions (> 10,000 counts) in an MS scan were automatically obtained. If the ion intensity was less than 10,000, MS/MS data acquisition was not performed and moved to the next top 10 ions. rformed and moved to the next top 10 ions.
|
