Lignin Quantification of Papyri by TGA—Not a Good Idea
Florian Bausch,
Dickson D. Owusu,
Paul Jusner,
Mario J. Rosado,
Jorge Rencoret,
Sabine Rosner,
José C. del Río,
Thomas Rosenau,
Antje Potthast
Affiliations
Florian Bausch
Department of Chemistry, Institute of Chemistry for Renewable Resources, University of Natural Resources and Life Sciences Vienna (BOKU), Konrad-Lorenz-Straße 24, A-3430 Tulln, Austria
Dickson D. Owusu
Department of Chemistry, Institute of Chemistry for Renewable Resources, University of Natural Resources and Life Sciences Vienna (BOKU), Konrad-Lorenz-Straße 24, A-3430 Tulln, Austria
Paul Jusner
Department of Chemistry, Institute of Chemistry for Renewable Resources, University of Natural Resources and Life Sciences Vienna (BOKU), Konrad-Lorenz-Straße 24, A-3430 Tulln, Austria
Mario J. Rosado
Instituto de Recursos Naturales y Agrobiología de Sevilla, CSIC, Avenida Reina Mercedes, 10, E-41012 Seville, Spain
Jorge Rencoret
Instituto de Recursos Naturales y Agrobiología de Sevilla, CSIC, Avenida Reina Mercedes, 10, E-41012 Seville, Spain
Sabine Rosner
Department of Integrative Biology and Biodiversity Research, Institute of Botany, University of Natural Resources and Life Sciences Vienna (BOKU), Gregor-Mendel Straße 33, A-1180 Vienna, Austria
José C. del Río
Instituto de Recursos Naturales y Agrobiología de Sevilla, CSIC, Avenida Reina Mercedes, 10, E-41012 Seville, Spain
Thomas Rosenau
Department of Chemistry, Institute of Chemistry for Renewable Resources, University of Natural Resources and Life Sciences Vienna (BOKU), Konrad-Lorenz-Straße 24, A-3430 Tulln, Austria
Antje Potthast
Department of Chemistry, Institute of Chemistry for Renewable Resources, University of Natural Resources and Life Sciences Vienna (BOKU), Konrad-Lorenz-Straße 24, A-3430 Tulln, Austria
Papyri belong to the oldest writing grounds in history. Their conservation is of the highest importance in preserving our cultural heritage, which is best achieved based on an extensive knowledge of the materials’ constituents to choose a tailored conservation approach. Thermogravimetric Analysis (TGA) has been widely employed to quantify cellulose and lignin in papyrus sheets, yielding reported lignin contents of 25% to 40%. In this work, the TGA method conventionally used for papyrus samples was repeated and compared to other lignin determination approaches (Klason-lignin and acetyl bromide-soluble lignin). TGA can lead to a large overestimation of the lignin content of commercial papyrus sheets (~27%) compared to the other methods (~5%). A similar overestimation of the lignin content was found for the pith and rind of the native papyrus plant. We concluded that the TGA method should, therefore, not be used for lignin quantification.
