Ionic liquid matrices for MALDI mass spectrometry of lignin.

The use of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry for the study of lignin is still extremely limited due to its low ionization efficiency. We have developed an approach for obtaining high-intensity MALDI mass spectra of lignin, based on the use of ionic liquids as matrices. Thirty-two ionic liquids consisting of large nitrogen-containing cations and anions of aromatic acids, traditionally used as crystalline matrices, were tested.

Formation of low molecular weight oligomers from chitin and chitosan stimulated by plasma-assisted processes.

The controlled degradation of solid powders of chitin and chitosan stimulated by electron-beam plasma (EBP) was experimentally studied. Crab shell chitin and chitosan were used as original substances. The non-equilibrium low temperature EBP was generated by injecting an electron beam into a gaseous medium.

Negative ion mode atmospheric pressure ionization methods in lignin mass spectrometry: A comparative study.

Rationale: Mass spectrometry with atmospheric pressure ionization is the most promising method for studying the structure of natural lignin, which is the second most abundant biopolymer in nature. The goal of this study is to compare the efficiency and characteristics of different types of ionization techniques (ESI, APCI, and APPI) in the negative ion mode by the example of softwood lignin.

Methods: As the subjects of the study, we selected a preparation of spruce dioxane lignin and several phenols, simulating the basic structural fragments of the lignin macromolecule.