Search for: All records

RationaleEffective 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. MethodsSynthesized 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. ResultsThe 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/z1823 for the FeCl₃system) 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). ConclusionsThe 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.