| dc.contributor.author | Isaac-Olive, Keila. | en_US |
| dc.date.accessioned | 2014-10-21T12:33:21Z | |
| dc.date.available | 2005 | |
| dc.date.issued | 2005 | en_US |
| dc.identifier.other | AAINR00971 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/54701 | |
| dc.description | Iodine is considered one of the essential trace elements for humans. Iodine deficiency disorder is common in Africa and Asia. In countries such as Canada and the United States there are concerns over the high levels of iodine intake. There is an increasing interest in the speciation analysis of iodine in bovine milk which is one of the main sources of this element for humans. | en_US |
| dc.description | One of the objectives of this thesis was to develop neutron activation analysis (NAA) methods of high precision, accuracy and sensitivity for measuring the iodine content of milk. Instrumental NAA (INAA), epithermal INAA (EINAA), and pseudo-cyclic INAA (PCINAA) methods using conventional and Compton suppression (CS) gamma-ray spectrometry were developed. The lowest detection limit of 0.02 mug.mL-1 was obtained using PCINAA-CS followed by 0.06 mug.mL-1 by both INAA-CS and EINAA-CS methods. Both relative and k0 methods for calculating concentrations gave high precision and accuracy. The expanded uncertainty of the relative method was estimated as 4.5%. | en_US |
| dc.description | One of the main objectives of this thesis was to do speciation analysis of iodine in bovine milk. A solvent extraction method was first employed for the separation of extractable organic compounds such as lipids. The organic extract was further separated using solid phase extraction into apolar, less polar and polar groups. The apolar group was then fractionated into hydrocarbons, tri-acylglycerides, di- and mono-acylglycerides, and free fatty acids. Ion exchange chromatographic methods were developed for the separation of inorganic iodine species. | en_US |
| dc.description | In summary, the total iodine content of milk was found to be 0.457 +/- 0.008 mug.g-1. The major iodine species was iodide ions with a concentration of 0.333 +/- 0.009 while iodate was 0.064 +/- 0.003 mug.g-1. Amounts of 0.034 +/- 0.003 and 0.013 +/- 0.003 mug.g-1 were protein- and lipid-bound iodine, respectively. Of the total protein-bound iodine, casein had 0.026 +/- 0.001 mug.g-1 and the rest (0.011 +/- 0.006 mug.g-1) was whey proteins. Fractionations of the lipid-bound iodine revealed that the amounts of apolar, less polar and polar classes were 11 +/- 3, 1.3 +/- 0.4, and 0.074 +/- 0.005 ng.g-1, respectively. Further fractionation of the apolar extract gave 3.4 +/- 0.3, 2.9 +/- 0.3, 2.0 +/- 0.2, and 3.3 +/- 0.4 ng.g-1 of hydrocarbons, triacylglycerols, di- and mono-acylglycerols, and free fatty acids, respectively. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 2005. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Chemistry, Analytical. | en_US |
| dc.subject | Engineering, Agricultural. | en_US |
| dc.subject | Health Sciences, Nutrition. | en_US |
| dc.subject | Chemistry, Agricultural. | en_US |
| dc.title | Speciation of iodine in bovine milk by neutron activation analysis. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
