6545 esi q tof ms

Using an Agilent UHPLC-MS system made up of an Agilent 1290 Infinity II UHPLC connected to an Agilent 6545 ESI-Q-TOF–MS in both negative and positive modes, aliquots (1 µl) of methanol extracts at a concentration of 2 mg/mL were examined. The following were the chromatographic conditions: Flow rate is 0.4 mL/min, a Kinetex phenyl-hexyl (1.7 µm, 2.1 50 mm) column was eluted with an isocratic elution of 90% H₂O/MeCN for 1 min, followed by a 6-min linear gradient elution to 5% H₂O/MeCN with 0.1% isocratic formic acid as modifier. The capillary temperature was set to 320 °C, the source voltage to 3.5 kV, and the sheath gas flow rate was set to 11 L/min for ESI. Ions identified with an intensity greater than 1000 counts per scan at 6 scans/s, with an isolation width of 1.3 m/z, a maximum of 9 selected precursors per cycle, and ramping collision energy (5 m/z/100 + 10 eV). Purine C₅H₄N₄ [M + H]⁺ ion (m/z 121.0508) and hexakis (1H,1H,3H-tetrafluoropropoxy)-phosphazene C₁₈H₁₈F₂₄N₃O₆P₃ [M + H]⁺ ion (m/z 922.0098) were used as internal lock masses for positive mode while TFA C₂HF₃O² [M − H]⁻ ion (m/z 112.9855) and hexakis (1H,1H,3H-tetrafluoropropoxy)-phosphazene C₁₈H₁₈F₂₄N₃O₆P₃ [M + TFA − H]⁻ion (m/z 1033.9881) were used as internal lock masses for negative mode.

Ultra-high-performance liquid chromatograms (UPLCs) were obtained on an Agilent LC-MS system composed of an Agilent 1290 Infinity II UPLC coupled to an Agilent 6545 ESI-Q-TOF-MS in negative ionization mode. Aliquots (1 µL) of RO and YO peel extracts (1 mg/mL in MeOH) were analyzed on a Kinetex phenyl-hexyl (1.7 µm, 2.1 × 50 mm) column eluted with 1 min isocratic elution of 90% A (A: 100% H₂O + 0.1% formic acid) followed by 6 min linear gradient elution to 100% B (95% MeCN + 5% H₂O + 0.1% formic acid) with a flow rate of 0.4 mL/min. ESI conditions were set with the capillary temperature at 320 °C, source voltage at 3.5 kV, and a sheath gas flow rate of 11 L/ min. Ions were detected in the full scan at an intensity above 1000 counts at 6 scans/s, with an isolation width of 1.3 ~m/z, a maximum of 9 selected precursors per cycle, and using ramped collision energy (5 × m/z/100 + 10 eV) [41 (link)]. The acquired MS/MS data were processed as Agilent Mass Hunter data files (.d).