Fourier Transform Ion Cyclotron Resonance Mass Spectrometric Study of Bio-oils

Abstract

This work uses ultrahigh resolution electrospray ionisation Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) coupled to negative- and positive- ion electrospray ionisation (ESI (-) and (+) ) to determine the molecular composition of six bio-oils. The results exhibited that the samples consist of a range 2981 to 7746 individual molecular compositions that refer to species were identified by negative- and positive ESI for each sample. The species cover a mass range between m/z 100–650 with up to 60 carbon atoms with a maximum number of 36 rings and double bonds. The presence of phosphorous species in bio-oils was investigated. However, it could not be determined clearly due to the need for a considerably higher resolving power than what was achieved in the experiment even by applying accurate mass measurements method and comparison of isotope pattern structure. For example, phosphorus and sodium cannot be distinguished at achieved resolving power 601,121 at m/z 403.078842. According to the FTICR MS results, the dominant constituents of the bio-oils refers to highly oxygenated species which correspond to compound class Ox species. A set of more than 3600 molecular assignments were identified in common within the samples by both negative- and positive ESI, also around up to 2438 distinctive assignments were identified as a unique composition for each bio-oil.