A new method based on nano-liquid chromatography coupled to time-of-flight mass spectrometry (nano-LC-TOF-MS) using lock-mass calibration was developed to facilitate the accurate and routine characterization and quantification of phenolic compounds. Thus, it was applied to study cranberry syrups, in which, using negative ionization mode, a total of nine phenolic compounds were unequivocally identified using standards and 38 tentatively taking into account their retention time, accurate mass (errors