Sodium selenite

Overview

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Sodium selenite powder

Sodium selenite is an inorganic compound with the formula Na₂SeO₃. It is a colorless solid that is soluble in water and is commonly used as a dietary supplement and in various industrial applications. Sodium selenite is one of the most common water-soluble forms of selenium, an essential trace element for many organisms.

Chemical Properties

Sodium selenite is a salt of selenous acid and is composed of sodium cations (Na⁺) and selenite anions (SeO₃^2_). It is typically obtained by the neutralization of selenous acid with sodium hydroxide. The compound is stable under normal conditions but can decompose upon heating to release toxic selenium dioxide (SeO₂) and sodium oxide (Na₂O).

Biological Role

Selenium, in the form of sodium selenite, plays a crucial role in the human body. It is a component of several selenoproteins and enzymes, including glutathione peroxidase, which protect cells from oxidative damage. Selenium is also important for thyroid hormone metabolism and immune system function.

Uses

Sodium selenite is used in animal feed and human dietary supplements to prevent selenium deficiency. It is also employed in glass manufacturing to decolorize glass and in the production of selenium-containing pigments. In biochemistry, sodium selenite is used as a source of selenium in cell culture media.

Safety and Toxicity

While selenium is essential in small amounts, sodium selenite can be toxic at higher concentrations. Overexposure can lead to selenosis, a condition characterized by symptoms such as gastrointestinal distress, hair loss, and neurological damage. It is important to handle sodium selenite with care and adhere to recommended dietary allowances.

Related Pages

• Selenium
• Selenoprotein
• Glutathione peroxidase
• Selenosis