University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Master / Diploma Thesis:
Julia Wenger
(2016):
Cellulose derived chromophores in pulp and paper: Analysis with Atmospheric Pressure Ionization Mass Spectrometry and Gas Chromatographic Methods.
Master / Diploma Thesis - Abteilung für Chemie nachwachsender Rohstoffe,
BOKU-Universität für Bodenkultur,
pp 126.
UB BOKU
obvsg
- Abstract:
- Analytical methods which are able to identify and quantify compounds that contribute to the discoloration of cellulosic material play an important role for the production of high quality products in the pulp and paper industry; research on naturally formed chromophores in historical documents leads to a better understanding of natural aging processes. High requirements on the analytical approach are posed, as the already identified key chromophores occur in very low concentrations (ppm and ppb range) in both historic and modern bleached papers, but they still cause a yellowish appearance. Based on the chromophore release and identification (CRI) approach, the aim was to develop highly sensitive methods with less expenditure of labor and sample amount. Analysis with desorption electrospray ionization (DESI) and paper spray (PS) mass spectrometry (MS) as well as gas chromatography (GC) coupled to an electron capture detector (ECD) are such promising approaches. Regarding DESI-MS and PS-MS, derivatization of the envisaged compounds is necessary in order to increase sensitivity and selectivity. In addition, application of high resolution mass spectrometry (HRMS) also assists in suppressing background signals from the paper matrix itself. Several derivatization approaches and two calibrations were carried out and are further discussed. With respect to GC based methods analysis with an electron capture detector (ECD) was carried out after application of appropriate derivatization approaches. GC followed by the rather mild chemical ionization technique coupled to a high resolution mass spectrometer (time-of-flight MS) proved to be a reasonable method for identifying the targeted derivatives. Several derivatization reagents were tested and are discussed. One derivatization approach, namely trifluoroacetylation of key chromophores, was identified as the most promising and hence, a calibration was established for GC-ECD which provided the basis for further investigations.
- Beurteilende(r): Potthast Antje
- 1.Mitwirkender: Böhmdorfer Stefan