title: Enhanced Mass Defect Filtering To Simplify and Classify Complex Mixtures of Lignin Degradation Products.
abstract: High resolution mass spectrometry was utilized to study the highly complex product mixtures resulting from electrochemical breakdown of lignin. As most of the chemical structures of the degradation products were unknown, enhanced mass defect filtering techniques were implemented to simplify the characterization of the mixtures. It was shown that the implemented ionization techniques had a major impact on the range of detectable breakdown products, with atmospheric pressure photoionization in negative ionization mode providing the widest coverage in our experiments. Different modified Kendrick mass plots were used as a basis for mass defect filtering, where Kendrick mass defect and the mass defect of the lignin-specific guaiacol (C7H7O2) monomeric unit were utilized, readily allowing class assignments independent of the oligomeric state of the product. The enhanced mass defect filtering strategy therefore provided rapid characterization of the sample composition. In addition, the structural similarities between the compounds within a degradation sequence were determined by comparison to a tentatively identified product of this compound series. In general, our analyses revealed that primarily breakdown products with low oxygen content were formed under electrochemical conditions using protic ionic liquids as solvent for lignin.
authors.affiliation: Institute of Bioanalytical Chemistry, Saarland University , 66123 Saarbrücken, Germany.
authors.forename: Tobias K F
authors.initials: TK
authors.lastname: Dier
authors.affiliation: Institute of Bioanalytical Chemistry, Saarland University , 66123 Saarbrücken, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Egele
authors.affiliation: Institute of Physical Chemistry, Saarland University , 66123 Saarbrücken, Germany.
authors.forename: Verlaine
authors.initials: V
authors.lastname: Fossog
authors.affiliation: Institute of Physical Chemistry, Saarland University , 66123 Saarbrücken, Germany.
authors.forename: Rolf
authors.initials: R
authors.lastname: Hempelmann
authors.affiliation: Institute of Bioanalytical Chemistry, Saarland University , 66123 Saarbrücken, Germany.
authors.forename: Dietrich A
authors.initials: DA
authors.lastname: Volmer
mesh_terms: D055664:Electrochemical Techniques; D008031:Lignin / Q000737:chemistry* / Q000378:metabolism*; D013058:Mass Spectrometry / Q000379:methods*; D008968:Molecular Conformation
chemical_list: D008031:Lignin