Selenite, sodium

In 1956 selenium was identified (123) as an essential micronutrient iu nutrition. In conjunction with vitamin E, selenium is effective iu the prevention of muscular dystrophy iu animals. Sodium selenite is adrninistered to prevent exudative diathesis iu chicks, a condition iu which fluid leaks out of the tissues white muscle disease iu sheep and infertility iu ewes (see Eeed ADDITIVES). Selenium lessens the iacidence of pneumonia iu lambs and of premature, weak, and stillborn calves controls hepatosis dietetica iu pigs and decreases muscular inflammation iu horses. White muscle disease, widespread iu sheep and cattle of the selenium-deficient areas of New Zealand and the United States, is insignificant iu high selenium soil areas. The supplementation of animal feeds with selenium was approved by the U.S. EDA iu 1974 (see Eeed additives). Much of selenium s metaboHc activity results from its involvement iu the selenoproteia enzyme, glutathione peroxidase. 

Sodium selenate has been used on a small scale in commercial greenhouses, primarily for growing carnations and chrysanthemums. It is transformed by the plants into volatile selenides, which repel red spiders, mites, thrips, and aphids (see Insect control technology). Sodium selenite is not intended for crops which could ultimately be used as food for humans or domestic animals. 

Sodium selenite has also been incorporated into styrene—butadiene mbber and used in a pellet form which results in the slow release of selenium into water. These pellets have been placed in lakes in Sweden which have fish contaminated with mercury owing to high levels of that element in the water. The selenium released by the pellets reacts with mercury to form insoluble, heavy mercury selenide which setties to the lake bottom and removes mercury from the ecosystem (126). 

For arsenic (added as sodium arsenate) and selenium (added as sodium selenite), losses were insignificant in all the container materials considered, irrespective of matrix composition. 

Zinc chalcogenide thin hlms have been grown by ECALE using zinc sulphate as metal source and sodium sulphide and sodium selenite as chalcogenide precursors.145-148 The formation of the hrst layers of ZnS on (lll)Au has been analyzed by STM and XPS.145 HRSEM images showed that the him surface was very hat, even at an atomic level. On the other hand, thicker ZnS hlms were formed of well-separated crystal nuclei. The stoichiometry of a thicker ZnS him showed a slight excess of sulphur, with a Zn S ratio of 1 1.2. The band gap of a thicker him (deposition time 12 h) was 3.60eV.147... 

Cadmium chalcogenide thin hlms have been grown by ECALE using cadmium sulphate as metal source and sodium sulphide, sodium selenite,... 

Adults fed diets 6 weeks before egg laying through day 7 of incubation containing either sodium selenite — at 1, 5, 10, or 25 mg Se/kg ration — or selenomethionine at 10 or 16 mg Se/kg ration... 

Selenomethionine group had altered immune function, altered serum enzyme activities, and elevated concentrations of selenium in liver (4 times control values) and breast muscle (14 times). Sodium selenite-treated birds had normal immune function and selenium tissue burdens however, serum enzyme activity was disrupted in the 3.5 mg/L group Adults normal. Impaired reproduction (reduced survival of ducklings, increased developmental abnormalities) for selenomethionine occurs between 4 and 8 mg/kg ration selenocysteine did not impair reproduction at 16 mg Se/kg ration... 

Ducklings fed diets containing 0, 10, 20, 40, or 80 mg Se/kg ration as selenomethionine or sodium selenite from hatching to age 6 weeks... 

Fairbrother, A. and J. Fowles. 1990. Subchronic effects of sodium selenite and selenomethionine on several immune-functions in mallards. Arch. Environ. Contamin. Toxicol. 19 836-844. 

Ort, J.F. and J.D. Latshaw. 1978. The toxic level of sodium selenite in the diet of laying chickens. Jour. Nutr. 108 1114-1120. 

Yonemoto, J., H. Satoh, S. Himeno, and T. Suzuki. 1983. Toxic effects of sodium selenite on pregnant mice and modification of the effects by Vitamin E or reduced glutathione. Teratology 28 333-340. 

In order to balance mineral intake, the following minerals were used in place of the usual mineral mix (% of diet) potassium chloride, 0.32 magnesium oxide, 0.084 manganous carbonate, 0.0123 ferric nitrate, 0.021 zinc carbonate, 0.0056 cupric carbonate, 0.0011 potassium iodate, 0.0004 sodium selenite, 0.00003 chromium potassium sulfate, 0.00193. 

Rees CB, Thode HG (1966) Selenium isotope effects in file reduction of sodium selenite and of sodium selenate. Can J Chem 44 419-427... 

Sodium selenite [10102-18-8] Daphnia magna EC50 (48-h) 0.40 Mayer and Ellersieck, 1986... 

Compounds Selenium dioxide selenium trioxide selenium oxychloride sodium selenite sodium selenate hydrogen selenide selenic acid selenium sulfide selenium disulfide... 

Reaction with sodium selenate yields lead selenate, PbSe04. Similarly, with sodium selenite or selenious acid, the product is lead selenite, PbSeOs. 

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