Accucore c18 2.6 m

Samples were diluted in methanol. High-resolution mass spectrometry analyses (HPLC-HRMS/MS) were performed in a Thermo Scientific QExactive© Hybrid Quadrupole-Orbitrap Mass Spectrometer. Analyses were performed in positive mode with m/z range of 133.4–2000; capillary voltage at 3.5 kV; source temperature at 250 °C; and S-lens 100 V. The stationary phase was a Thermo Scientific column Accucore C18 2.6 µm (2.1 mm × 100 mm × 1.7 µm). The mobile phase was 0.1% formic acid (A) and acetonitrile (B). Eluent profile (A/B %): 95/5 up to 2/98 within 10 min, maintaining 2/98 for 5 min, down to 95/5 within 1.2 min and maintaining for 8.8 min. Total run time was 25 min for each run and flow rate was 0.2 mL.min⁻¹. Injection volume was 3 µL. MS/MS was performed by collision-induced dissociation (CID) with m/z range of 100–800 and the collision energy ranged from 10 to 50 V. MS and MS/MS data were processed with Xcalibur software (version 3.0.63) developed by Thermo Fisher Scientific, Waltham, MA, USA.

Crude extracts of the seeds, pulp, and total fruit of açaí (Euterpe oleracea Mart.) were suspended in 2 mL of MeOH HPLC and centrifuged at 13,000 rpm for 5 min. The supernatant solution (100 µL) was filtered through 0.22 µm and diluted into 900 µL MeOH HPLC. The samples were analyzed using an LC Agilent 1200 mass spectrometer coupled with an Agilent iFunnel 6550 Q-ToF LC/MS. The electrospray ionization source operated in positive mode ESI (+) following operating conditions: nebulizing gas temperature, 290 °C; capillary voltage, +3500 V; nozzle voltage, 320 V; drying gas flow, 12 mL min⁻¹; nebulization gas pressure, 50 psig; auxiliary gas temperature, 350 °C; and flow of auxiliary gas, 12 mL min⁻¹. The analyzer’s time-of-flight (ToF) was operated in the range of m/z 50–1500. Collision energy formula (auto MS/MS mode): 4 V (slope) × (m/z)/100 + 5 V (offset). A maximum of five precursors per cycle were selected. Stationary phase: Thermo Scientific Accucore C18 2.6 µm, 2.1 mm × 100 mm. Mobile phase: acetonitrile and 0.1% formic acid. Flow rate: 0.2 mL/min⁻¹. The organic phase was run in gradient mode from 5% to 98% within 10 min, held for 5 min, up to 5% within 1.2 min, and held for 4.8 min. Total run time: 20 min. The injection volume used was 2 µL. The spectra were processed using Agilent Mass Hunter Workstation Software.