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Gewählte Master / Diploma Thesis:

Claudia Lourdes Laguna Paredes (2009): Jod in Hühnereiern: Erprobung verschiedener Analysenmethoden und Messung der aktuellen Jodgehalte in österreichischen Eiern.
Master / Diploma Thesis - Abteilung Tierische Lebensmittel, Tierernährung und Ernährungsphysiologie (TTE), BOKU-Universität für Bodenkultur, pp 108. UB BOKU obvsg

Data Source: ZID Abstracts
Abstract:
Iodine, as an essential trace element, must be taken through the food. Its main function unfolds iodine as a central component of thyroid hormones ((T3) or (T4)). In fact, Austria is an iodine deficiency area. The present work aimed to improve the iodine analysis and knowledg about actual iodine content in eggs. To improve the iodine analytics, composite samples of eggs and feed were tested with three digestion methods: the alkaline extraction with ammonia respectively with tetramethylammonium hydroxide (TMAH), and the acid digestion with potassium chlorate / nitric acid. The derived solutions have been investigated in an ICP-MS for their concentrations of iodine, on the basis of an internal standard (tellurium 125 and bromine 81) or the standard addition method. The acid digestion proved to be the most reliable method of sample preparation. However, also here were still significant matrix effects, so that a reliable measurement of the iodine content of the extracted sample solutions was only on standard addition procedure possible. In a second step, samples of eggs were taken out from 34 commercial laying hen farms and their level of iodine was analyzed via acid digestion and the standard addition method. The diets contained 1093 ± 779 μg J / kg, which corresponds to the native levels of the individual components and the usual practice of iodine supplement on the mineral feed. The iodine concentrations in the wet weight of egg white, egg yolk and egg mass of edible egg (white + yolk) were 0.07±0.08, 1.58±0.99 and 0.55±0.35 μg/g. The quantities of iodine in a medium egg were (61 g total mass, 36 g of egg white, yolk were 17 g, 8 g shell) at 29 μg iodine (2 μg in egg white, 27 μg in the yolk). Eating an egg in the Austrian Central covers about one fifth of the recommended intake of iodine by an adult (150 μg/day). This is a significant contribution to the iodine supply.

Beurteilende(r): Windisch Wilhelm Matthias

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