Thesis by Alexis Dubuis*

The development of production processes for fuel and platform moleculesa from lignocellulosic biomass requires knowledge of the chemical composition, on a molecular scale, of the various liquid products generated. But the complexity of the latter makes it necessary to incorporate a “deformulation” step upstream of the actual analysis, without causing any loss or modification of the compounds present.

This thesis research related to two original fractionation methods based, on the one hand, on solubility, with liquid-liquid extraction (LLE) techniques and centrifugal partition chromatography (CPC) and, on the other hand, molecular size with steric exclusion chromatography (SEC). LLE and CPC are used for the selective extraction of sugars, neutral compounds (furans, aldehydes, ketones, alcohols, esters), carboxylic acids and phenols(1-2) while SEC is used for a more specific sugar separation(3). The actual analysis was then conducted on each fraction obtained, via reversed-phase liquid chromatography, with ultraviolet and mass spectrometry detection (RPLC-UV/MS).

SECxRPLC/MS (left) and CPCxRPLC/MS (right) maps obtained for a product derived from the biochemical
conversion of wheat straw.

The pretreatment and deformulation steps not only enable a simplification of the samples to be analyzed but also structuring on the basis of the properties of the chromatograms generated, thereby facilitating their exploitation. The innovative 2D maps generated contain an abundance of information on the chemical composition of the bioproducts (figure). For an even more detailed characterization, this methodology could be combined with chemometric data analysis.

*Thesis entitled "Deformulation of complex biomass-based matrices and characterization via liquid phase chromatography combined with mass spectrometry"

a - Molecules used as a building block in numerous applications

L. Chahen, E. Destandau, N. Charon, Journal of Chromatography A (2020), 1610.

(2) A. Dubuis, A. Le Masle, L. Chahen, E. Destandau, N. Charon. Journal of Chromatography A (2019) 1597.

(3) A. Dubuis, A. Le Masle, L. Chahen, E. Destandau, N. Charon. Journal of Chromatography A (2020) 1609.

Scientific contact : agnes.le-masle@ifpen.fr