title: A comparative study of matrix- and nano-assisted laser desorption/ionisation time-of-flight mass spectrometry of isolated and synthetic lignin.
abstract: BACKGROUND
  Lignin is the second most abundant biopolymer next to cellulose. However, because of the complexity of the heterogeneous macromolecules, it is difficult to elucidate the polymeric structures of lignin by conventional analytical methods.
  
  
  OBJECTIVE
  To obtain the detailed structures of lignin, we comparatively applied nano-assisted laser desorption/ionisation time-of-flight mass spectrometry (NALDI-TOF MS) and matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS).
  
  
  METHODS
  Synthetic lignin from coniferyl alcohol and an isolated lignin from Pinus densiflora were subjected to NALDI- and MALDI-TOF MS.
  
  
  RESULTS
  We first obtained NALDI-TOF MS of synthetic and isolated lignin. Mass increments of 178 and 196 Da were observed in NALDI- and MALDI-TOF mass spectra of the synthetic and isolated lignin. The mass intervals indicated that radical coupling forming β-O-4 bonds is the major pathway. Peaks in the low molecular mass region between m/z 500 and 800 were observed more extensively using NALDI-TOF MS than MALDI-TOF MS, which enabled detailed analysis of the interunit linkages in lignin.
  
  
  CONCLUSIONS
  Owing to the ionisation profile differentiation from MALDI-TOF MS, NALDI-TOF MS is useful for the structural analysis of lignin.
authors: Laboratory of Biomass Conversion, Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan.
authors: Koichi
authors: K
authors: Yoshioka
authors: Daisuke
authors: D
authors: Ando
authors: Takashi
authors: T
authors: Watanabe
mesh_terms: D008031:Lignin / Q000032:analysis* / Q000138:chemical synthesis / Q000302:isolation & purification; D008956:Models, Chemical; D015394:Molecular Structure; D036103:Nanotechnology / Q000379:methods; D028223:Pinus / Q000737:chemistry*; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D008031:Lignin