Off-line LC×SFC-HRMS/MS non-target analysis of depolymerised lignin (Eliise Tammekivi, MDCW 2024)

🎤 Presenter: Eliise Tammekivi¹, Magali Batteau¹, Dorothée Laurenti², Karine Faure¹ (¹Institute of Analytical Sciences, Universite Claude Bernard Lyon 1, CNRS, Villeurbanne, France. ²Ircelyon, Universite Claude Bernard Lyon 1, CNRS, Villeurbanne, France)

💾 PDF presentation

💡 Book in your calendar: 16th Multidimensional Chromatography Workshop (MDCW) 3 - 5. February 2025

Abstract

Lignin is an abundant natural polymer that is by far the largest natural resource for aromatic compounds. Nevertheless, approx. only 2% of it is commercialised while the rest is mainly burned to power the paper industry, from which lignin is obtained by fractionating cellulose from lignocellulosic biomass. However, it has the potential to be valorised more by isolating valuable aromatic compounds, incorporating into materials (e.g., coatings, resins, thermoplastics), or used as biofuel. For making these valorisation processes efficient, thorough structural characterisation via a powerful chromatographic technique can be highly beneficial as the complex composition of lignin depends on the botanical origin, isolation, and depolymerisation processes.

Therefore, an off-line comprehensive two-dimensional (2D) chromatography method combining liquid chromatography, supercritical fluid chromatography, and high-resolution mass spectrometry with fragmentation (LC×SFC-HRMS/MS) was developed. The implementation of a 1-aminoanthracene column in the second dimension enabled a good class separation of lignin monomers, dimers, trimers, and tetramers with additional separation based on the number of hydroxyl groups and steric effects. The pentafluorophenyl column in the first dimension additionally improved the separation based on hydrophobicity, thus the first 2D-LC plot demonstrating classification of lignin compounds was obtained. The comparison of the technique to 1D-SFC showed that the 2D-LC method is also superior for separating isomers, which is especially beneficial for lignin as 77% of the detected compounds had at least one isomer. Advanced data analysis methods (MS-DIAL, SIRIUS, and FBMN) were integrated into the non-target workflow to rapidly visualise and study the detected compounds.