Thesis (MSc)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: The phenolic content of wine is responsible for determining characteristics such as the
organoleptic qualities, colour stability, ageing properties and health-beneficial effects
associated with wine. The aim ofthis study was to investigate the possibilities offered by
capillary electrophoresis (CE) as an alternative separation technique to high performance
liquid chromatography (HPLC) for the analysis of polyphenols in wine. The complexity
of wine samples was the cause that neither technique was capable of a satisfactory singlestep
analysis of wine. Suitable sample preparation techniques such as Sephadex- and Sep-
Pak fractionation and ether extraction of wine polyphenols were investigated. These
techniques did not, however, prove to be universal. A novel form of sample preparation
namely a process analogous to lyophylization used to separate wine volatiles from nonvolatiles
was introduced.
The versatility of CE was further investigated in an attempt to eliminate the need for
sample preparation. The use of polyvinylalcohol (PVA) coated capillaries, micellar
electrokinetic chromatography (MEKC) and capillary gel electrophoresis (CGE) were
investigated in this regard. Although none of these techniques could offer conclusive
results, useful applications were forthcoming and routes for further investigation were
outlined. Liquid chromatography coupled to electro spray ionisation mass spectroscopy
(LC-ESI-MS) and capillary electrophoresis coupled to electro spray ionisation mass
spectroscopy (CE-ESI-MS) were compared for the analysis of polyphenols in wine.
While the latter technique could not produce sufficient separation compared to the
former, future development ofCE-ESI-MS should make it a powerful technique for these
analyses. / AFRIKAANSE OPSOMMING: Die fenoliese komponente in wyn speel 'n bepalende rol by eienskappe soos die
organoleptiese karakter, kleur stabiliteit, verouderingspotensiaal en gesondheids-voordele
wat met wyn geassosieër word. Die doel van hierdie projek was om ondersoek in te stel
na die potensiaal wat kapillêre elektroforese (CE, "capillary electrophoresis") as 'n
alternatiewe skeidingstegniek teenoor hoë druk vloeistof chromatografie (HDVC) vir die
analise van die polifenole in wyn bied. Die kompleksiteit van wyn monsters is van so 'n
aard dat 'n bevredigend enkelstap analise met geeneen van die tegnieke moontlik is nie.
Gepaste monster-voorbereidingstappe soos Sephadex- en Sep-Pak fraksionering asook
eter ekstraksie van die polifenole in wyn is ondersoek. Geeneen van die tegnieke was
egter universeel toepaslik nie. 'n Nuwe metode van monster-voorbereiding, naamlik 'n
proses analoog aan liofilisasie wat gebruik word om die wyn te skei in vlugtige en nievlugtige
komponente is gedemonstreer.
Die veelsydigheid van CE was gevolglik ondersoek in 'n poging om
monstervoorbereiding uit te skakel. Die gebruik van polyvinielalkohol-(pVA) bedekte
kapillêre, missellêre elektrokinetiese chromatografie (MEKC) en kapillêre gel
elektroforese (CGE, "capillary gel electrophoresis) is in hierdie verband ondersoek.
Alhoewel geeneen van hierdie tegnieke onweerlegbare resultate gelewer het nie, het
bruikbare toepassings hieruit voortgespruit en is die grondslag vir verdere navorsing gelê.
Vloeistof chromatografie gekoppel aan eIektrosproei ionisasie massaspektroskopie (LCESI-
MS) en kapillêre elektroforese gekoppel aan elektrosproei ionisasie massaspektroskopie
(CE-ESI-MS) is vergelyk vir die analise van polifenole in wyn. Alhoewel
laasgenoemde tegniek onvoldoende skeiding lewer vergeleke met eersgenoemde, behoort
toekomstige ontwikkelinge op die gebied van CE-ESI-MS dit 'n kragtige tegniek vir die
analise van hierdie monsters te maak.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/51753 |
| Date | 03 1900 |
| Creators | De Villiers, A. J. (Andre Joubert) |
| Contributors | Sandra, P. J. F., Lauer, H. H., Stellenbosch University. Faculty of Science . Dept. of Chemistry & Polymer Science . |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 89 p. |
| Rights | Stellenbosch University |
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