Radioactive iodide

Sodium Iodide, Radioactive, Sodium iodide—,MI sodium radio-iodide (tslI) Na l iodotope Oriodide Radiocaps-131 Theriodide-131. Prepd from radioactive iodine ( l) which has a half-life of 8 days and emits beta and gamma rays. Other properties identical with those of ordinary sodium iodide. Dispensed as carrier-free sodium radioiodide in capeules for oral use Or in aq soln for oral or parenteral administration. 

Phosphine Potassium iodide Radioactive iodine and methyl chloride Potassium iodide... 

In a classic expenment Edward Hughes (a colleague of Ingold s at University College Lon don) studied the rate of racemization of 2 lodooctane by sodium iodide in acetone and compared It with the rate of incorporation of radioactive iodine into 2 lodooctane... 

To prevent such release, off gases are treated in Charcoal Delay Systems, which delay the release of xenon and krypton, and other radioactive gases, such as iodine and methyl iodide, until sufficient time has elapsed for the short-Hved radioactivity to decay. The delay time is increased by increasing the mass of adsorbent and by lowering the temperature and humidity for a boiling water reactor (BWR), a typical system containing 211 of activated carbon operated at 255 K, at 500 K dewpoint, and 101 kPa (15 psia) would provide about 42 days holdup for xenon and 1.8 days holdup for krypton (88). Humidity reduction is typically provided by a combination of a cooler-condenser and a molecular sieve adsorbent bed. 

If the spent fuel is processed in a nuclear fuel reprocessing plant, the radioactive iodine species (elemental iodine and methyl iodide) trapped in the spent fuel elements ate ultimately released into dissolver off gases. The radioactive iodine may then be captured by chemisorption on molecular sieve 2eohtes containing silver (89). 

To prevent radioactive iodides from lodging in the thyroid gland during exposure to excessive radiation, a potential appHcation of iodine acting as a thyroid-blocker has arisen. Eor this purpose potassium iodide was recommended (66). 

The radioactive isotopes available for use as precursors for radioactive tracer manufacturing include barium [ C]-carbonate [1882-53-7], tritium gas, p2p] phosphoric acid or pP]-phosphoric acid [15364-02-0], p S]-sulfuric acid [13770-01 -9], and sodium [ I]-iodide [24359-64-6]. It is from these chemical forms that the corresponding radioactive tracer chemicals are synthesized. [ C]-Carbon dioxide, [ C]-benzene, and [ C]-methyl iodide require vacuum-line handling in weU-ventilated fume hoods. Tritium gas, pH]-methyl iodide, sodium borotritide, and [ I]-iodine, which are the most difficult forms of these isotopes to contain, must be handled in specialized closed systems. Sodium p S]-sulfate and sodium [ I]-iodide must be handled similarly in closed systems to avoid the Uberation of volatile p S]-sulfur oxides and [ I]-iodine. Adequate shielding must be provided when handling P P]-phosphoric acid to minimize exposure to external radiation. 

Synthetic chemical approaches to the preparation of carbon-14 labeled materials iavolve a number of basic building blocks prepared from barium [ CJ-carbonate (2). These are carbon [ C]-dioxide [ CJ-acetjlene [U— C]-ben2ene, where U = uniformly labeled [1- and 2- C]-sodium acetate, [ C]-methyl iodide, [ C]-methanol, sodium [ C]-cyanide, and [ CJ-urea. Many compHcated radiotracers are synthesized from these materials. Some examples are [l- C]-8,ll,14-eicosatrienoic acid [3435-80-1] inoxn. [ CJ-carbon dioxide, [ting-U— C]-phenyhsothiocyanate [77590-93-3] ftom [ " CJ-acetjlene, [7- " C]-norepinephrine [18155-53-8] from [l- " C]-acetic acid, [4- " C]-cholesterol [1976-77-8] from [ " CJ-methyl iodide, [l- " C]-glucose [4005-41-8] from sodium [ " C]-cyanide, and [2- " C]-uracil [626-07-3] [27017-27-2] from [ " C]-urea. All syntheses of the basic radioactive building blocks have been described (4). 

The selective uptake of iodide ion by the thyroid gland is the basis of radioiodine treatment in hyperthyroidism, mainly with although various other radioactive isotopes ate also used (40,41). With a half-life of eight days, the decay of this isotope produces high energy P-particles which cause selective destmction within a 2 mm sphere of their origin. The y-rays also emitted are not absorbed by the thyroid tissue and are employed for external scanning. 

Strong iodide solutions act by decreasing the vascularity of the thyroid gland by rapidly inhibiting the release of the thyroid hormones. Radioactive iodine is distributed within the cellular fluid and excreted. The radioactive isotope accumulates in the cells of the tiiyroid gland, where destruction of tiiyroid cells occurs without damaging other cells throughout the body. 

Radioactive iodine is given by tlie primary health care provider, orally as a single dose The effects of iodides are evident within 24 hours, with maximum effects attained after 10 to 15 days of continuous therapy. If the patient is hospitalized, radiation safety precautions identified by the hospital s department of nuclear medicine are followed. 

Excess production of thyroid hormone can be reduced in four ways iodides, antithyroid drugs, radioactive iodine, and... 

The displacement was monitored by observing the changing distribution of radioactive 128I between the inorganic (sodium) iodide and 2-iodooctane, and it was found, under these conditions, to be second order overall (first order with respect to 128Ie and to 2-iodooctane) with k2 = 3-00 + 0-25 x 10-5 (at 30°). 

Radioactive 11C-methyl labeling for study of methanol co-reaction with methyl iodide on Fe -Beta zeolite... 

The adsorption of methanol as well as methyl iodide was complete at ambient temperature on Fe-Beta-300 (917 m2/g surface area) since radioactive gas was not detected at catalyst outlet. Only a small part of methyl iodide (conversion rate was 10-25 %) while most part of methanol was converted (conversion rate was 60-90 %) up to... 

C-methanol co-reaction with non-radioactive methyl iodide on Fe-Beta-300 The 11 C-methanol with non-radioactive methyl iodide was investigated to study the modification of the methanol reaction mechanism in co-reaction with methyl iodide. 

The radioactive signals of radio-GC show the 1 -methanol derivates and its common derivates with non radioactive methyl iodide (Fig. lb). The nC-methanol derivates take part in new molecule formation with non-radioactive methyl iodide or/and its derivates on catalyst surface. The C-methyl iodide as a newly formed radioactive product was detected while the selectivity to hydrocarbons sharply decreased (Fig. 2b). 

C-methyl iodide co-reaction with non-radioactive methanol... 

EGER targeting was also used for systemic delivery of pDNA expressing the sodium iodide symporter (NIS) gene to liver cancer cells, followed by administration of radioactive isotope iodine-131, which accumulates in the tumor by NIS-mediated uptake in radiotherapeutic doses [227]. 

Figure 12.4 IODO-BEADS contains immobilized chloramine-T groups that can react with radioactive iodide in...

---