Eclipse plus c18 column

The LC-MS/MS system consisted of Agilent 1290 Infinity HPLC system and Agilent 6530 Accurate-Mass Quadrupole Time-of-Flight (Q-TOF) mass spectrometer equipped with dual AJS ESI ion source (Agilent Technologies Korea, Seoul, Korea). Chromatographic separation was performed on an Agilent Eclipse Plus C18 column (2.1 × 100 mm, 3.5 μm) with a Phenomenex Security Guard C18 guard column (4 × 20 mm) maintained at 40 °C. The mobile phase consisted of 0.1% formic acid in deionized water (A) and 0.1% formic acid in CH₃CN (B): 0~2 min 5% B, 2~7 min to 95% B, and 7~10 min 95% B. Total run time including a 5 min equilibration time was 15 min. The flow rate was 0.4 mL/min. The injection volume was 5 µL. The mass spectrometer was operated in a positive Auto MS/MS scan mode with a full scan mass range of m/z 100–1000, fragmentor voltage 150 V, and CE 30 eV, selecting the two most intense precursor ions for collision-induced dissociation. Putative metabolites were identified using Agilent Mass Hunter Metabolite ID software (ver.B.04.00) followed by manual interpretation of the spectral data. Chromatograms and mass spectra were extracted using Agilent Mass Hunter Qualitative Analysis software (ver. B.05.00).

RP-HPLC analyses were performed with a JASCO modular HPLC system (Tokyo, Japan, model PU 2089) coupled to a diode array apparatus (MD 2010 Plus). The HPLC was equipped with an injection valve with a 20 μl sampling loop and an Eclipse-PLUS-C18 column (25 mm × 0.46 cm, 5 μm; Phenomenex, Bologna, Italy) at a flow rate of 1.0 ml/min. The identification and quantification of different polyphenols in the extracts of agri-food waste were performed following the experimental conditions also used by Tacchini et al. (caftaric acid and flavonoids) (22 (link)), Bernardi et al. (anthocyanins) (23 (link)), and Kammerer et al. (gallic acid and catechins) (24 (link)). The different peaks were identified by comparing their UV spectra and retention times with those of pure standards. Dedicated JASCO software (ChromNAV version 2.02.01) was used to calculate peak areas by integration. Each experiment was performed in triplicate.