Rationale: Effective analytical techniques are needed to characterize lignin products for the generation of renewable carbon sources. Application of matrix-assisted laser desorption/ionization (MALDI) in lignin analysis is limited because of poor ionization efficiency. In this study, we explored the potential of cationization along with a 2,5-dihydroxyacetophenone (DHAP) matrix to characterize model lignin oligomers. Methods: Synthesized lignin oligomers were analyzed using the developed MALDI method. Two matrix systems, DHAP and α-cyano-4-hydroxycinnamic acid (CHCA), and three cations (lithium, sodium, silver) were evaluated using a Bruker UltraFlextreme time-of-flight mass spectrometer. Instrumental parameters, cation concentration, matrix, sample concentrations, and sample spotting protocols were optimized for improved results. Results: The DHAP/Li + combination was effective for dimer analysis as lithium adducts. Spectra from DHP and ferric chloride oligomers showed improved signal intensities up to decamers (m/z 1823 for the FeCl 3 system) and provided insights into differences in the oligomerization mechanism. Spectra from a mixed DHP oligomer system containing H, G, and S units showed contributions from all monolignols within an oligomer level (e.g. tetramer level). Conclusions: The DHAP/Li + method presented in this work shows promise to be an effective analytical tool for lignin analysis by MALDI and may provide a tool to assess lignin break-down efforts facilitating renewable products from lignin.
|Number of pages||9|
|Journal||Rapid Communications in Mass Spectrometry|
|State||Published - Apr 30 2019|
Bibliographical noteFunding Information:
Funding for this research was provided by the National Science Foundation EPSCoR Track 2 (OIA 1632854).
National Science Foundation, Grant/Award Number: OIA 1632854
Funding for this research was provided by the National Science
© 2019 John Wiley & Sons, Ltd.
ASJC Scopus subject areas
- Analytical Chemistry
- Organic Chemistry