2D Assignment and quantitative analysis of cellulose and oxidized celluloses using solution-state NMR spectroscopy

  • PDF / 3,173,182 Bytes
  • 25 Pages / 547.087 x 737.008 pts Page_size
  • 91 Downloads / 154 Views

DOWNLOAD

REPORT


(0123456789().,-volV) ( 01234567 89().,-volV)

ORIGINAL RESEARCH

2D Assignment and quantitative analysis of cellulose and oxidized celluloses using solution-state NMR spectroscopy Tetyana Koso . Daniel Rico del Cerro . Sami Heikkinen . Tiina Nypelo¨ . Jean Buffiere . Jesus E. Perea-Buceta . Antje Potthast . Thomas Rosenau . Harri Heikkinen . Hannu Maaheimo . Akira Isogai . Ilkka Kilpela¨inen . Alistair W. T. King Received: 15 April 2020 / Accepted: 25 June 2020  The Author(s) 2020

Abstract The limited access to fast and facile general analytical methods for cellulosic and/or biocomposite materials currently stands as one of the main barriers for the progress of these disciplines. To that end, a diverse set of narrow analytical techniques are typically employed that often are time-consuming, costly, and/ or not necessarily available on a daily basis for practitioners. Herein, we rigorously demonstrate a general quantitative NMR spectroscopic method for structural determination of crystalline cellulose samples. Our method relies on the use of a readily accessible ionic liquid electrolyte, tetrabutylphosphonium acetate Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10570-020-03317-0) contains supplementary material, which is available to authorized users. T. Koso (&)  D. Rico del Cerro  S. Heikkinen  J. E. Perea-Buceta  I. Kilpela¨inen  A. W. T. King (&) Materials Chemistry Division, Department of Chemistry, Faculty of Science, University of Helsinki, Kumpula Campus, Helsinki, Finland e-mail: [email protected] A. W. T. King e-mail: [email protected] T. Nypelo¨ Division of Applied Chemistry, Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg, Sweden

([P4444][OAc]):DMSO-d6, for the direct dissolution of biopolymeric samples. We utilize a series of model compounds and apply now classical (nitroxyl-radical and periodate) oxidation reactions to cellulose samples, to allow for accurate resonance assignment, using 2D NMR. Quantitative heteronuclear single quantum correlation (HSQC) was applied in the analysis of key samples to assess its applicability as a high-resolution technique for following cellulose surface modification. Quantitation using HSQC was possible, but only after applying T2 correction to integral values. The comprehensive signal assignment of the diverse set of cellulosic species in this study constitutes a blueprint for the direct quantitative structural elucidation of crystalline lignocellulosic, in general, readily available solution-state NMR spectroscopy. J. Buffiere Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, Espoo, Finland A. Potthast  T. Rosenau Institute for Chemistry of Renewables, Department of Chemistry, University of Natural Resources and Life Sciences Vienna (BOKU), Wien, Austria H. Heikkinen The Finnish Institute for the Verification of the Chemical Weapons Convention (VERIFIN), Helsinki, Finland H. Maaheimo VTT Technical Research