Natural iodine

Fabryka-Martin, X, Bentley, H., Elmore, D., Airey, P. L. (1985) Natural iodine-129 as an environmental tracer. Geochim. Cosmochim. Acta, 49, 337-47. 

There are two iodine Mdssbauer resonances. The 27-72-keV transition of I was first observed in 1962 by Jha, Segnan, and Lang [67]. The 57-60-keV transition of I was reported in 1964 by Barros et al. [68]. Both have been used extensively in chemical investigations. The resonance has the better nuclear properties for MOssbauer work, with the unfortunate exception that the ground state is radioactive with a half-life of 1-7 x 10 y. Because of this, I absorbers must be specially prepared and handled, whereas natural iodine comprises the stable I in 100% abundance. 

The natural iodine offer of animals and man without iodine supplementation greatly varies with distance from the seaside, the geological origin of the site, the eating habits and the specific iodine contents of the various foods and beverages (Table 9-4.15). The danger of an iodine deficiency is most severe in grazing ruminants (wild and domestic) and lowest in carnivores. Animals and people with mixed diets are also... 

Iodine is mainly found in marine material. Salt water fish, shellfish, and seaweed are food sources with the highest natural iodine content. Seaweed has a very high iodine content one bowl of soup made by tangle, which is a common soup... 

Dietary iodine is found in food, iodi2ed salt, milk and drinking water in the form of iodide or iodate of potassium, calcium, or sodium (Venkatesh and Dunn, 1995). Certain diets are naturally iodine-rich, while others contain very little iodine. Furthermore, it is known that certain geographical regions are iodine-poor (e.g., mountainous areas), and lower economic status may afford less variable food products, resulting in limited access to iodine-containing or iodine-enriched foods. 

Other Countries in this book). In other countries with a known ID, despite national efforts to implement the mandatory use of iodi2ed salt, (e.g., in Switzerland, Italy and Spain), mild-to-moderate ID is still present in certain counties or geographical areas (Als et al, 2000 Caron et al., 1997). In addition, iodine intake may vary unexpectedly, because of significant variations in the natural iodine content of local food and water, and because of the variability in response to supplementation (Nohr et al., 1993 Nohr and Laurberg, 2000). Therefore, a close monitoring of trimester-specific thyroid functions is recommended. 

Iodine is an important trace element, which is highly related to humans. Iodine deficiency can lead to abnormal growth in humans. In nature, iodine becomes enriched in marine organisms and sediments that provide the largest reservoir. The distribution of iodine in marine sediments has a trend of increasing from low latitude to high latitude. 

In 1811, Bernard Courtois discovered natural iodine in water that was used to dissolve certain parts of seaweed ash for use. Radioactive iodine-131 was discovered by Glenn T. Seaborg and John Livingood at the University of California - Berkeley in the late 1930 s. 

Iodine has as many as 37 isotopes, many of which happen to be radioactive. Further to this, many of these isotopes form in the event of a nuclear explosion, and should they be released into the atmosphere it s advisable to take iodine supplements to prevent the natural iodine in the thyroid gland from being replaced by a radioactive type. This helps mitigate the risk of cancer forming in the thyroid gland. 

The purpose of this question is to find out whether any passive sink for the iodine has been provided to supplement the natural iodine removal mechanisms, like deposition, adsorption, chemical reaction, mass transfer into the water pool or into the droplets, and pool scrubbing, etc. Table 6 presents a summary of the responses. Except the borax used in the ice condenser of the Loviisa units (Finland) no other passive means have been reported. 

In two separate beakers, you prepare saturated solutions of Pbl2 in contact with the solid. One beaker contains only natural iodine atoms with nonradioactive isotopes. The other beaker contains radioactive iodide ion, Some of the solution, but no solid, containing the radioactive iodide ion is now added to the beaker containing nonradioactive iodide ion. Both solutions are saturated, so the amount of solid in this beaker remains constant. Yet after a time the solid lead iodide, which was originally nonradioactive, becomes radioactive. This is evidence for a dynamic equilibrium, in which radioactive iodide ions in the solution substitute for nonradioactive iodide ions in the solid. 

A very mild means of oxidation of trialkylboranes to the corresponding alcohols is provided in the stoicheiometrically controlled reaction with oxygen at least a portion of the reaction is free-radical in nature, iodine acting as an inhibitor this leads to some loss of stereospecificity in cases leading to chiral alcohols. If the oxidation is performed at low temperature in dilute solution, alkyl hydroperoxides are obtained. ... 

Field concentration methods can be used to increase the quantity of in certain materials that are collected. Thus, particle filters and activated charcoal filters have been used to collect atmospheric iodine (Brauer et al., 1974a). Ion-exchange methods, usually using anion exchange resins, have been used to sample water-borne iodine and ionic iodine in milk (Daly et al., 1974 Brauer and Rieck, 1973 Brauer et al., 1974b Keisch et al., 1965). Natural iodine collectors, such as thyroid tissue and seaweed, have been used for collection of environmental I samples (Brauer et al., 1974b Keisch et al., 1964 NSEC, 1963 Boulos et al., 1973 Kelleher and Michael, 1973 Smith, 1977 Oliver et al., 1982 Schuttelkopf and Pimpl, 1982). 

Brauer, F.P. and Kaye, J.H. (1974). Detection systems for the low-level radiochemical analysis of iodine-131, iodine-129, and natural iodine in environmental samples, IEEE Trans. Nucl. Sci. 21,446. 

Brauer, F.P., Soldat, J.K., Tenny, H. and Strebin, R.S., Jr. (1974b). Natural iodine and iodine-129 in mammalian thyroids and environment samples taken from locations in the United States, page 43 in Environmental Surveillance Around Nuclear Installations II, IAEA Publication No. STI/PUB/353 (International Atomic Energy Agency, Vienna). 

This Isotope has been produced from natural Iodine by the following reactions ... 

Iodine-128 has been made by the bombardment of natural Iodine with thermal neutrons (103, 235) I(n,Y) I. 

The great bulk of the work which has been done on neutron activation anal-ysis for iodine has dealt with natural iodine-127 ( I(n,Y) I), and the procedures described below are concerned primarily with that isotope. Because of the growing interest in the long-lived, fission-produced iodine-129 (1.57 x 10 y), the section is concluded with a method for the sequential analysis of low levels of iodine-131, iodine-129, and natural iodine in environmental samples based on chemical separation and neutron activation analysis techniques. 

In a procedure for the determination of natural iodine in solid samples of biological materials (230), I" and iodide carrier were added to the irradiated sample and the mixture was heated in a solution of chromium (VI) oxide in concentrated sulfuric acid. The mixture was cooled and diluted, and phosphorous acid was added to convert the iodine to iodide. The latter was then oxidized to elemental iodine by the addition of sodium nitrite, and the iodine was distilled into aqueous sodium hydroxide which contained Dowex 2-X8 resin (OH form). The mixture was shaken, the liquid decanted and the resin counted. Chemical yields of 80-90% were obtained. Where further purification was desired, the resin was washed with sodium nitrate solution to elute chlorine-38 activity, the most likely contaminant. Such treatment decreased the yields to 60-70%. 

A procedure for the analysis of natural iodine in aqueous solutions of iodohippuric acid (57) has utilized a freezing technique for the preparation of the sample for irradiation. Irradiation of a frozen sample rather than a solution has a number of advantages, the pressure in irradiation containers caused by the radiolysis of water is reduced substantially losses of iodine due to vaporization and also to adsorption on container walls are greatly minimized and interference from nuclides from container walls is avoided. 

Brauer, F. P. and Kaye, J. H. Detection Systems for the Low-Level Radiochemical Analysis of Iodine-131, Iodine-129, and Natural Iodine In Environmental Samples. IEEE (Inst. Elec. Electron. Eng.), Trans. Nucl. Scl. NS-iL. No. 1, 496 (1974). 30 5867... 

Bauer, F. P., Soldat, J. K., Tenny, H., and Strebin, R. S., Jr. (BNWL-SA-4694) Natural Iodine and Iodine-129 in Manmalian Thyroids and Environmental Samples Taken from Locations in the United States. 1973. 28 p. (CONF-731117-1 SM-180/34). Dep. NTIS. 29 5099... 

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