Screening of Phenolic Compounds in Aqueous Extracts of Pyrolysis Oils by High-Resolution Mass Spectrometry

Bio-oil has been obtained from biomass undergoing pyrolysis to yield a complex mixture of organic compounds from different classes. The high content of oxygenated hydrocarbons distinguishes bio-oil from fossil-derived oils with similar properties. Bio-oil can also be used as a feedstock for chemicals due to its rich phenolic composition. Phenolic compounds possess significant industrial value and have been used in industrial sectors for the manufacture of antioxidants, resins, pharmaceuticals, and plastics. Although confirmatory analysis of these compounds is important, it has already been reported in the literature through chromatography hyphenated to mass spectrometry. Thus, this study aimed to obtain a fast and simple screening of suspect phenolic compounds in bio-oil obtained from lignocellulosic biomass (pine wood residue, sugarcane straw, and sugarcane bagasse). Instrumental conditions were optimized for negative electrospray ionization quadrupole time-of-flight mass spectrometry (ESI(−)Q-TOF MS) for screening compounds present in the aqueous phase of bio-oils obtained by pyrolysis of lignocellulosic biomass. A simple extraction method was used to prepare the samples for screening by ESI(−)Q-TOF MS. A total of 21 compounds (primary phenolics) were identified.