New Fourier transform infrared (FTIR) approaches for the quantitative determination of peroxide value (PV) and isolated trans analyses were investigated and developed. The FTIR-PV methods investigated were all based on the stoichiometric reaction of hydroperoxides and triphenylphosphine (TPP) which converts TPP to triphenylphosphine oxide (TPPO). A reference transmission cell (100 mum) method was developed based on the use of a unique TPPO absorption at 542 cm-1. This method covered PV values from 0--15 PV and was shown to be superior in accuracy and reproducibility to the standard American Oil Chemists Society (AOCS) iodometric method. Subsequently, the utility of disposable polyethylene cards, normally used only for qualitative analyses, was investigated for quantitative PV determination. A quantitative IR card method was successfully developed and shown to serve as a very simple, rapid and alternative means of carrying out PV analyses. TPP-impregnated cards were able to reproduce the transmission cell PV results to +/-1.12 PV, while the unimpregnated card was slightly more accurate (+/-0.92 PV). A third FTIR-PV method was developed specifically for the at-line monitoring of high PV fatliquors and employed a germanium attenuated total reflectance sample handling accessory. This method hinged on the use of a TPPO absorption band at 1118 cm-1, normally off scale when pathlengths of >3 mum are used, but is suited to the analysis of oils having very high PVs (>250). The successful quantitative use of the disposable polyethylene IR card to PV led to its study for the quantitative FTIR determination of the isolated trans content of fats and oils and margarines. The polyethylene card was shown to unique and useful properties, tending to inhibit fat crystallization and its inability to retain moisture. These two properties allowed trans determination to be carried out on melted, high trans fats, without heating the polyethylene substrate and also to analyze margarines
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.36643 |
| Date | January 2000 |
| Creators | Ma, Kangming, 1965- |
| Contributors | van de Voort, F. R. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Food Science and Agricultural Chemistry.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001764650, proquestno: NQ64609, Theses scanned by UMI/ProQuest. |
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