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The US Food and Drug Administration approved a selenium supplement to animal diets; the most common form is sodium selenite for pet foods. According to one article, "not much was known about which selenium compounds to approve for use in animal feeds when the decisions were made back in the 1970s ..
[3] [4] It is suitable for food and laboratory uses. Reagent grade is almost as stringent as the ACS grade. USP grade meets the purity levels set by the United States Pharmacopeia (USP). USP grade is equivalent to the ACS grade for many drugs. NF grade is a purity grade set by the National Formulary (NF). NF grade is equivalent to the ACS grade ...
Sodium selenate is produced by oxidation of selenium, first with nitric acid, producing selenous acid. The selenous acid is neutralized to form sodium selenite. The sodium selenite is oxidized in a basic medium hydrogen peroxide to form a selenate, which is then spray-dried. [3] Se + 2HNO 3 → H 2 SeO 3 + NO + NO 2 H 2 SeO 3 + Na 2 CO 3 → Na ...
Selenium trioxide is produced in the laboratory by the reaction of anhydrous potassium selenate (K 2 SeO 4) and sulfur trioxide (SO 3). [7] Salts of selenous acid are called selenites. These include silver selenite (Ag 2 SeO 3) and sodium selenite (Na 2 SeO 3). Hydrogen sulfide reacts with aqueous selenous acid to produce selenium disulfide:
The USP is published in a combined volume with the National Formulary (a formulary) as the USP-NF. [2] If a drug ingredient or drug product has an applicable USP quality standard (in the form of a USP-NF monograph), it must conform in order to use the designation "USP" or "NF".
SeO 2 is considered an acidic oxide: it dissolves in water to form selenous acid. [6] Often the terms selenous acid and selenium dioxide are used interchangeably. It reacts with base to form selenite salts containing the SeO 2− 3 anion. For example, reaction with sodium hydroxide produces sodium selenite: SeO 2 + 2 NaOH → Na 2 SeO 3 + H 2 O
Selenium yeast is a feed additive for livestock, used to increase the selenium content in their fodder. It is a form of selenium currently approved for human consumption in the EU and Britain. [1] Inorganic forms of selenium are used in feeds (namely sodium selenate and sodium selenite, which appear to work
Selenite refers to the anion with the chemical formula Se O 2− 3. It is the oxyanion of selenium. It is the selenium analog of the sulfite ion, SO 2− 3. Thus selenite is pyramidal and selenium is assigned oxidation state +4. Selenite also refers to compounds that contains this ion, for example sodium selenite Na 2 SeO 3 which is a common ...