Iodine extraction

An iodine extraction method was used to isolate the tin-113 from the irradiation mixture as 113Snl4. The desired organotin compound, butyltin-113 trichloride, was prepared by first converting the 113SnI4 into 113SnCl4 by treatment with anhydrous tin tetrachloride. Then, heating the tin-113 tetrachloride with an excess of tetrabutyltin for three hours at 110°C (equation 34) yielded butyltin-113 trichloride. 

Short-lived iodine fission products have also been separated by a similar method. In this case, an oxidant such as nitrite ion in acidic aqueous solution has been used (50,255) the iodine extracted into carbon tetrachloride, and then back-extracted into an aqueous solution containing sodium hydrosulphite (50). 

Iodine extraction from waste solutions from niter production ... 

In 1881, Bernard Courtois (1777-1838) introduced another halogen, iodine, extracting the element from wracks at the seashore. William Wallace proposed iodine tincture in 1835 to disinfect wounds. It was superseded by iodoform, which was less of an irritant, invented by Georges Simon Serullas (1774-1832). Structurally, it was very comparable to chloroform, the chlorine atom being substituted by an iodine one. Aqueous iodine solutions were proposed by Casimir Davaine (Lugol s solution) as antiseptics. 

Extraction of iodine contained in organic (humic and fulvic) components of the soils was performed by shaking 2g soil samples in 20 ml of 5% TMAH, using a table shaker, for 4h. The mixture was then centrifuged, and the supernatant analyzed using ion chromatography and inductively coupled plasma mass spectrometry (ICP-MS). Using the NIST SRM soils with well-known total iodine contents, we also evaluated extraction variables, such as the temperature (TMAH extraction under either room temperature or 80°C), on quantitative iodine extraction. 

Spiked iodine Extraction Each Dupiicate pass pass Totai... 

Inorganic labile iodine, extractable from a low ion-strength salt, comprised less than 10% of the total iodine in surface soils. This is consistent with the reports that approximately 80% of 183 UK soils contained less than 10% cold-water extractable iodine (cf. Fuge and Johnson, 1986). For some soil samples, we also evaluated the proportion of iodide and iodate in inorganic iodine (Table 10.7), and it seems that either may be dominant. We are not aware of other reports on the distribution of iodide and iodate in soil iodine. Yamada et al. (1999) assumed that iodide is more soluble than iodate, and used the first... 

An aliquot of free iodine extract from Table 3 was tested for bactericidal activity. A = water-soluble formulation, B = partially water-soluble formulation and C = experimental water-insoluble formulation. 

The radioiodine content of milk can be determined on the basis of iodine extraction from milk with tetrachloromethane (carbon tetrachloride). In this way, only inorganic iodine in milk is determined, and organically bound iodine is obtained after alkali metal fusion and extraction. The activity is measured after the precipitation of silver iodide. 

RNAA procedure, elemental I2 was extracted with chloroform in the second procedure, it was precipitated as Agl. The lowest I detection limit of 1 ng/g was achieved by the first procedure. Agl contained some traces of impurities increasing the detection limit, while the detection limit of INAA was two orders of magnitude higher. The chemical yield of the procedure was determined using a radiotracer. The procedure was used by Kucera et al. (2004, 2007) for the determination of I in Asian diets. The iodine extraction procedure was applied with slight modifications by several others (Dermelj and Byrne 1997). I2 was also separated by distillation from the sample and retention on Mn02 followed by purification via distillation according to Pietra et al. (1986). 

Accelerator mass spectrometry (AMS) is useful to measure extremely low-abundance nuclides (isotope ratio of 10 to 10 relative to its stable isotope), such as Be, C, A1, C1, " Ca, and I, in natural samples. Small amounts of C and T can be measured by AMS on mg size samples of carbon and iodine extracted from 500-ml seawater samples (Povinec et al. 2000). Neutron activation analysis (NAA), radiochemical neutron activation analysis (RNAA), and inductively coupled plasma mass spectrometry (ICP-MS) are useful for the determination of ultra-trace Th and U in geological and cosmochemical samples, and for determination of the concentration of Pu and Pu. Reference marine-biological samples are necessary to test the performance of the analytical methods employed in surveying and monitoring radioactive materials in the sea. An ocean shellfish composite material containing 0.1% w/w Irish Sea mussel, 12% w/w White Sea mussel, and 87.9% w/w Japan Sea oyster has been prepared as the NIST SRM 4358 (The National Institute of Standards and Technology, SRM) in the natural-matrix, environmental-level radioactive SRM series (Altzitzoglou 2000). This NIST SRM 4358 sample will be useful for the determination of the activity of K, Cs, Pb, Ra, Th, and Am. 

Some individual substances may however be chemically modified during this test. Nichaman et al. [475] have reported the iodination of polyunsaturated fatty acids and the results of the subsequent gas-liquid chromatography which were thereby rendered inaccurate. Localisation with iodine, extraction and quantitative determination with dichromate solution has been described for lipids [19] the interfering 10 ... 

Iodine with the Bresle patch. Sampling is performed according to the Bresle method (blister patch and hypodermic), but with different leaching liquids. The test surface is first prepared with an aqueous solution of iodine and then washed with distilled water. Extraction of the dissolved iodine in oil on the surface is thereafter made by the aid of a potassium iodide solution. After extraction of the initially absorbed iodine from the contaminated surface, starch is added to the potassium iodide solution. Assessment of the amount of iodine extracted from the surface is then determined from the degree of blue coloring of the solution. Because the extracted amount of iodine is a measure of the amount of oil residues on the surface, the concentration of the oil on the surface can be determined. 

For the production of I from Cs, the target, CsIO, was irradiated with fast neutrons obtained from the reaction of deuterons on beryllium (109). After irradiation, the cesium iodate was dissolved in an aqueous solution of molecular iodine and the iodine extracted into carbon tetrachloride. Several I,I redox cycles were then carried out and the iodine was finally precipitated as silver iodide. The product was contaminated with I and I (the extent of contamination was not given) formed from iodate. 

Iodine-136 has been separated from a solution of natural uranium which was Irradiated for 30 sec at a flux of about 5 x 10 n/cm /sec (62). Iodide carrier and sodium carbonate were added to the Irradiated solution and the iodine was oxidized with sodium hypochlorite. It was then reduced to the free state by means of hydroxylamlne In addle solution. An l2 redox cycle was then performed and elemental Iodine extracted Into carbon tetrachloride. The radio-chemical purity of the I at this stage was described as excellent. 

One method which gave a purification of iodine-131 from a 16-day-old solu-tion of 10 fissions had the following steps (224). Iodide, iodate, or periodate carrier and sodium chlorate were added to the sample which contained only inorganic substances (but no gold) and no reducing agents. The solution was made 6-10 in hydrochloric acid in order to produce iodine monochloride (yellow-green solution). The monochloride was extracted into butyl acetate and then back-extracted into water as iodide by means of sulfurous acid. Iodide was oxidized to elemental iodine with iron(III) chloride in dilute sulfuric acid and the iodine extracted into toluene. The element was back-extracted into water as iodide by sulfurous acid and palladium(II) iodide was precipitated. 

A method claimed to be applicable for a minimum detectable activity of less than 0.05 pCI/i of sample at the time of counting has been reported (86). Carrier was mixed with the milk sample and the mixture was heated to about 75°. Iodide was collected on an anion exchange resin (resin not specified) and then eluted as lodate by means of hypochlorite. lodate was converted to free Iodine by treatment with hydroxylamlne hydrochloride and sodium nitrite. An l2"I cycle was performed and the Iodine extracted Into toluene in which medium It was determined photometrically for chemical yield. 2-Methyl butene was added to the toluene solution and the liquid sample was mixed with a toluene-based liquid scintillation counting solution and 8-gated y coincidence counting was carried out. 

The Iodic acid effluent was neutralized with sodium hydroxide solution, boiled, and acidified with concentrated nitric acid. lodate was reduced to free Iodine by hydroxylamlne hydrochloride and the Iodine extracted Into benzene. Two l2 l"... 

Commercial production of iodine occurs almost exclusively in Japan and Chile, with iodine extracted from concentrated salt brine from underground wells, seaweed, or from Chilean saltpetre deposits. 

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