Fractionation of iodine in iodine-enriched algae Chlorella
Authors | |
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Year of publication | 2005 |
Type | Article in Proceedings |
Conference | European winter conference on plasma spectrochemistry 2005 |
MU Faculty or unit | |
Citation | |
Field | Analytic chemistry |
Keywords | Iodine; fractionation; Chlorella |
Description | Iodine as an essential element has a great importance in human and animal health. Concerning animal husbandry, feed fortified by iodine provides adequate supply of this element and influences the health of animals and the quality of production. The bioavailability of iodine depends on the form of iodine. This work deals with determination of iodine or selenium forms in enriched algae Chlorella that is cultivated in Institute of Microbiology (Czech Academy of Science) and consecutively applied in in-vivo experiments at University of Veterinary and Pharmaceutical Sciences. Fractionation protocol including sequential extraction by chloroform, water and sodium dodecylsulphate solution was designed. Inductively coupled plasma optical emission or mass spectrometry was employed for determination of element content in fractions. Fractions were solubilized with tetramethylammonium hydroxide for determination of iodine or digested with nitric acid at 160şC for determination of selenium. Inorganic non-metabolized anions (iodide, selenite) were quantified in aqueous extract using vapour-generation ICP-OES after separation on anion exchange resin. Fractionation gives information on the content of element in non-polar, protein, polar water-soluble and non-soluble organic fractions and inorganic anions. Methodology was applied in analysis of algae samples that were cultivated with different cultivating conditions (hetero- or autotrophic). Metabolization of iodine to organic forms is likely better for autotrophic cultivation, where higher content of organic-bound iodine can be found in algae biomass. In case of selenized algae, autotrophic cultivation results in higher total selenium content as well as higher percentage of protein-bound element compared to heterotrophic conditions. Results of this research are used in optimization of cultivation conditions to get desired composition of enriched Chlorella and as a starting point for further investigation of chemical forms of elements in algae. |
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