Iodine in food

Iodine in drinking water Iodine in food produets Selenium in drinking water... 

Mineral deficiencies are not uncommon and can have quite a variety of causes—e. g., an unbalanced diet, resorption disturbances, and diseases. Calcium deficiency can lead to rickets, osteoporosis, and other disturbances. Chloride deficiency is observed as a result of severe Cr losses due to vomiting. Due to the low content of iodine in food in many regions of central Europe, iodine deficiency is widespread there and can lead to goiter. Magnesium deficiency can be caused by digestive disorders or an unbalanced diet—e.g., in alcoholism. Trace element deficiencies often result in a disturbed blood picture—i. e., forms of anemia. 

Potassium iodide is found in seaweed. Some important appbcations of this compound involve its use in pharmaceuticals and as a source of iodine in food, especially in animal and poultry feed. Potassium iodide is added to table salt to provide iodine in human food. 

P. A. Fecher, I. Goldmann, A. Nagengast, Determination of iodine in food samples by inductively coupled plasma mass spectrometry after alkaline extraction, J. Anal. Atom. Spectrom., 13 (1998), 977D982. 

M. Haldimann, A. Eastgate, B. Zimerli, Improved measurement of iodine in food samples using inductively coupled plasma isotope dilution mass spectrometry, Analyst, 125 (2000), 1977-1982. 

Life Sciences Research OflBce, "Iodine in Foods Ghemical Methodology... 

S. Yang and S. H. Wang, Determination of trace iodine in food and biological samples by cathodic stripping voltammetry, Anal. Chem. 63 (24), 2970-3... 

USE Nutritional source of iodine in foods and feed stuffs. More stable in table salts than iodides Food Field Reporter, Ang. 8, 1956 Daum, C.A. 51, 5324 (1957) to improve properties of yeast-leavened bakery products. 

Larsen EH and Ludwigsen MB (1997) Determination of iodine in food-related certified reference materials using wet ashing and detection by inductively coupled plasma mass spectrometry. J Anal Atom Spectrom 12 435-439. 

The determination of iodine in food has been a difficult analytical problem for many years, and inconsistent results have been obtained in interlaboratory studies (Heckmann, 1979), although a variety of analytical methods capable of iodine determination at various levels in foodstuffs have been developed. The main difficulty is the volatility of iodine when present in the elementary form or in the forms of its volatile compounds. The procedures for iodine determination differ in decomposition methods, analytical principles, detection limits, specificity, accuracy and precision, robustness, and sensitivity to interference. From the practical point of view, they also differ in the ease of performance, equipment needed, and the time and costs involved. 

A low-cost assay of iodine in foods and urine can be performed using catalytic spectrophotometric methods, namely those based on the Sandell—Kolthoff reaction. These methods, however, are not optimal for determination of the lower range of iodine levels occurring in foodstuffs, because of possible interference. 

Iodide is the compound in which iodine is present in the -1 oxidation state and which is easily absorbed from the gastrointestinal tract and distributed to extracellular water in the human body. It is also in this form that it is pushed into the cells of the thyroid gland. Once inside the cell, it is activated by iodine peroxidase for the eventual synthesis of thyroxin. Since iodine is easily oxidized to elemental iodine, use of this form of iodine in foods could result in a change of color and affect organoleptic properties. The other commonly used form of iodine for fortification purposes is iodate, a form in which the element is present in the -I- 5 oxidation state. While this form is stable in various foods and is bioavailable (after being reduced to... 

In addition to iodized salt and natural forms of iodine in foods, there may be alternative sources of iodine, including... 

GC method has been developed for determination of total iodine in food, based on the reaction of iodine with 3-pentanone. Organic matter of a sample was destroyed by an alkaline ashing technique. Iodide in a water extract of the ash residues was oxidized in order to free I2 by adding Cr20/2- in the presence of H2SO4. Liberated iodine reacted with 3-pentanone to form 2-iodo-3-p>entanone, extracted into n-hexane, and then determined by gas chromatography with an electron-capture detector. Recoveries of L from spiked food samples ranged from 91.4 to 99.6%. Detection limit for iodine was 0.05 pg/g (Mitsuhashi KanedaY,1990). 

Fecher P. A., Goldman, 1. A. Nagengast. (1998). Determination Of Iodine In Food Samples By Inductively Coupled Plasma Mass Spectrometry After Alkaline Extraction. Journal of Analytical Atomic Spectometry, Vol.l3, pp 977-982, ISSN 1364-5544 Fernandez-Sanchez, L. Szpunar, J. (1999). Spedation Analysis For Iodine In Milk By Size -Exclusion Chromatography With Inductively Coupled Plasma Mass Spectrometric Detection (SEC-ICP MS). J.Anal. At. Spectrom., Vol.l4, pp 1697-1702, ISSN 1364-5544 Fernandez-Sanchez, L., Bermejo-Barreraa, P., Fraga-Bermudez, Szpunar, J. Lobinski R. 

Determination Of Iodine In Human Milk And Infant Formulas. Journal of Trace Elements in Medicine and Biology, Vol.21, Supp.l, pp 10-13, ISSN 0946-672X Fischer, P.W.F., Labbe, M. R. Giroux, A. (1986). Colorimetric determination of total iodine in foods by iodide-catalyzed reduction of Ce+4. J. Assoc. Off. Anal. Chem., Vol.69, No.4, pp 687 - 689, ISSN 0004-5756... 

The sample preparation procedure is mainly used for two purposes. The first purpose is distinguish different forms either for nutritional purposes, such as the determination of free or bounded iodine in food samples, or for differential toxicity so as to assess different fluorotensides in ecotoxicological experiments by their differential adsorption at an activated carbon surface. 

Procedures based on separation techniques such as HPLC and IC have been developed for single element analysis for the following two reasons. The first reason is to remove interferents in complicated sample matrices that can give rise to incorrect results, in particular for trace analysis in samples with a high organic content, such as the determination of total iodine in egg products. The second reason is to differentiate the total and free forms of a specific element, such as the determination of the free iodide ion and bounded iodine in food additives. The free iodide ion is determined by direct sample injection into the IC column, whereas the total iodine content is determined after oxygen flask combustion. Thus, both the free and bounded forms of iodine in food samples can be determined. 

Certain food additives contain iodine. For example, potassium iodate and calcium iodate are components of preparations for stabilising dough. The synthetic red food colouring erythrosine contains 58% iodine (fouriodineatomsinthemolecule).Therefore, foods coloured using this pigment have a higher iodine content, but the bioavailability of erythrosine iodine is low (2-5%). The content of iodine in foods and meals may also increase with the use of table salt fortified with iodine (as sodium iodide or sodium iodate). The iodine concentration in table salt is 20-50 mg/kg. 

Iodine is used by the thyroid gland to make hormones. Normally we ingest iodine in foods, especially iodized salt. The thyroid gland cannot tell the difference between stable and radioactive iodine and will absorb both. KI tablets work by blocking radioactive iodine from entering the thyroid. When a person takes KI, the stable iodine in the tablet gets absorbed by the thyroid. Because KI contains so much stable iodine, the thyroid gland becomes full and cannot absorb any more iodine—either stable or radioactive— for the next 24 hours. 

From Pennington, J.A. and Young, B.ilron, zinc, copper, manganese, selenium, and iodine in foods from the United States total diet study. J. Food Compos. Analysis 3 166, 1990. 

Endemic goitre has been eradicated from Australia which is now an iodine replete country. Average iodine intake is in excess of 200 ug/day. While there is no national iodine prophylaxis program there is an abundance of iodine in food due principally to high iodine levels in milk and dairy products. There is a need for Australia to develop and implement a national iodine surveillance program to prevent the return of iodine deficiency disorders. 

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