Fluorescently labeled cellulose nanofibrils for detection and loss analysis

Michael S Reid; Maria Karlsson; Tiffany Abitbol

doi:10.1016/j.carbpol.2020.116943

Fluorescently labeled cellulose nanofibrils for detection and loss analysis

Carbohydr Polym. 2020 Dec 15:250:116943. doi: 10.1016/j.carbpol.2020.116943. Epub 2020 Aug 26.

Authors

Michael S Reid¹, Maria Karlsson², Tiffany Abitbol³

Affiliations

¹ Department of Fiber and Polymer Technology, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden. Electronic address: mreid@kth.se.
² RISE Research Institutes of Sweden, SE-11428, Stockholm, Sweden; Linköping University, Department of Physics, Chemistry and Biology, SE-58183, Linköping, Sweden.
³ RISE Research Institutes of Sweden, SE-11428, Stockholm, Sweden. Electronic address: tiffany.abitbol@ri.se.

PMID: 33049855
DOI: 10.1016/j.carbpol.2020.116943

Abstract

Fluorescently labeled cellulose nanofibrils (CNFs) were used to evaluate CNF leaching from paper according to standard safety assays for food contact materials. Enzymatically pretreated pulp was first labeled with 5-([4,6-Dichlorotriazin-2-yl]amino)fluorescein hydrochloride (DTAF), followed by homogenization to produce fluorescent CNFs of varying degrees of fibrillation. Labeling at the μmolar DTAF/g cellulose level imparted quantitative ppb fluorescence detection of CNFs (LOD of approximately 20 ppb), without significantly altering other material properties, suggesting that DTAF-labeled CNFs are an appropriate mimic for native CNFs and that this approach can be used to detect low CNF concentrations. Cold and hot-water extractions of laboratory papers (100 % CNFs and CNF-fiber blended papers) showed loss values below 3 wt% CNFs, with the finest CNF quality showing the least loss overall and with greater loss experienced under hot water conditions compared with cold water. DTAF-labeled CNFs can be used to address questions related to CNF distribution, localization, and loss.

Keywords: Cellulose nanofibrils; Films; Fluorescent; Localization; Nanocellulose; Nanopapers; Papers; Product safety.