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Multidimensional fractionation of wood-based tannins
Thesis (MSc)--University of Stellenbosch, 2011.
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| Format: | Thesis |
| Language: | en_ZA |
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Stellenbosch : University of Stellenbosch
2011
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| _version_ | 1867613778841960448 |
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| access_status_str | Open Access |
| author | Radebe, Nonhlanhla Mtandi |
| author2 | Pasch, Harald |
| author_browse | Pasch, Harald Radebe, Nonhlanhla Mtandi |
| author_facet | Pasch, Harald Radebe, Nonhlanhla Mtandi |
| author_sort | Radebe, Nonhlanhla Mtandi |
| collection | Thesis |
| dc_rights_str_mv | University of Stellenbosch |
| description | Thesis (MSc)--University of Stellenbosch, 2011. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/6621 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:41:32.562Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2011 |
| publishDateRange | 2011 |
| publishDateSort | 2011 |
| publisher | Stellenbosch : University of Stellenbosch |
| publisherStr | Stellenbosch : University of Stellenbosch |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/6621 Multidimensional fractionation of wood-based tannins Radebe, Nonhlanhla Mtandi Pasch, Harald University of Stellenbosch. Faculty of Science. Dept. of Chemistry and Polymer Science. Chemistry of tannins High performance liquid chromatography Oligomeric proanthocyanidins Dissertations -- Polymer science Theses -- Polymer science Chemistry and Polymer Science Thesis (MSc)--University of Stellenbosch, 2011. ENGLISH ABSTRACT: High molar mass tannin extracts are complex mixtures which are distributed in both molar mass and chemical composition. Condensed tannins from quebracho and mimosa and hydrolysable tannins of tara, chestnut wood and turkey gall were studied. Application of a single analytical technique is not sufficient to elucidate the complete structures present in the extracts. 13C Nuclear Magnetic Resonance (NMR) spectroscopy and Matrix Assisted Laser Desorption/Ionisation Time-of-Flight (MALDI-TOF) mass spectrometry were applied in order to determine the chemical composition and molar mass, respectively. A new mass spectrometric method that can uniquely determine the oligomer microstructure was developed using Collision Induced Dissociation (CID) experiments. Bulk analysis only showed the average composition of the extracts, in order to obtain specific information on the molar mass and chemical composition distributions. Hydrophilic Interaction Liquid Chromatography (HILIC) was used for analysis of the condensed tannins and for the hydrolysable tannins Normal Phase Liquid Chromatography (NP-LC) was utilised. The HILIC separation was up-scaled and the fractions were collected and analysed by MALDI-TOF, and this coupling revealed that separation occurs by molar and chemical composition. For separation of the molecules only by size, Size Exclusion Chromatography (SEC) analyses were carried out; this allowed for relative comparison of the tannin molecules. In conclusion, for characterisation of high molar mass tannins a multi-dimensional approach was necessary since the various distributions present in these extracts are superimposed. AFRIKAANSE OPSOMMING: Hoë molekulêre massa tannienekstrakte is komplekse mengsels, in terme van beide molekulêre massa en chemiese samestelling. Gekondenseerde tanniene vanaf quebracho en mimosa, en hidroliseerbare tanniene vanaf tara, kastaaiinghout en Turksegal is bestudeer. Die gebruik van ‘n enkele analitiese tegniek is nie voldoende om die volledige struktuur van komponente teenwoordig in die ekstrakte te analiseer nie. 13C KMR-spektroskopie en MALDI-TOF-massaspektroskopie is gebruik om die chemiese samestelling en molekulêre massa, onderskeidelik, te bepaal. ‘n Nuwe metode is ontwikkel vir die bepaling van die oligomeer-mikrostruktuur deur gebruik te maak van botsings-geïnduseerde dissosiasie eksperimente. Grootmaat analise het net die gemiddelde samestelling van die ekstrak bepaal. Hidrofiliese-interaksie-vloeistofchromatografie (HILIC) is gebruik vir die analise van gekondenseerde tanniene en gewone fase-vloeistofchromatografie is gebruik vir die hidroliseerbare tanniene. Die HILIC-skeiding is op groter skaal uitgevoer en die fraksies is versamel en gebruik vir MALDI-TOF analise. Hierdie koppeling het getoon dat skeiding plaasvind op grond van molekulêre massa en chemiese samestelling. Grootte-uitsluitingschromatografie is gebruik vir die skeiding van molekules alleenlik op grootte. Hierdeur kon ‘n relatiewe vergelyking van die tannienmolekules gemaak word. Vir die karakterisering van hoë molekulêre massa tanniene is ‘n multi-dimensionele benadering nodig aangesien die verskeie verspreidings teenwoording in hierdie ekstrakte supergeponeerd is. 2011-03-07T05:56:17Z 2011-03-14T08:25:07Z 2011-03-07T05:56:17Z 2011-03-14T08:25:07Z 2011-03 Thesis http://hdl.handle.net/10019.1/6621 en_ZA University of Stellenbosch application/pdf Stellenbosch : University of Stellenbosch |
| spellingShingle | Chemistry of tannins High performance liquid chromatography Oligomeric proanthocyanidins Dissertations -- Polymer science Theses -- Polymer science Chemistry and Polymer Science Radebe, Nonhlanhla Mtandi Multidimensional fractionation of wood-based tannins |
| title | Multidimensional fractionation of wood-based tannins |
| title_full | Multidimensional fractionation of wood-based tannins |
| title_fullStr | Multidimensional fractionation of wood-based tannins |
| title_full_unstemmed | Multidimensional fractionation of wood-based tannins |
| title_short | Multidimensional fractionation of wood-based tannins |
| title_sort | multidimensional fractionation of wood based tannins |
| topic | Chemistry of tannins High performance liquid chromatography Oligomeric proanthocyanidins Dissertations -- Polymer science Theses -- Polymer science Chemistry and Polymer Science |
| url | http://hdl.handle.net/10019.1/6621 |
| work_keys_str_mv | AT radebenonhlanhlamtandi multidimensionalfractionationofwoodbasedtannins |