nitratenitrite

Nitratenitrite refers to compounds that contain nitrate (NO3−) or nitrite (NO2−) functional groups, and is sometimes used to describe mixtures of nitrate and nitrite salts. The two anions differ in the oxidation state of nitrogen: nitrate has nitrogen in the +5 state, while nitrite is +3. Common nitrate salts include sodium nitrate and potassium nitrate; common nitrite salts include sodium nitrite and potassium nitrite. In aqueous solution, these anions are typically highly soluble and participate in a variety of redox and acid–base reactions.

Nitrates are generally strong oxidizers and are widely used as fertilizers and in industrial processes, including ammunition manufacture. Nitrites, by contrast, are often reductants and have a long history as curing agents in processed meats, where they help preserve color and inhibit microbial growth. Nitrites also serve in chemical synthesis and can engage in complex redox chemistry in environmental and biological contexts. In some products, mixtures of nitrate and nitrite salts are used to balance preservation effects with flavor and appearance, though formulations vary by country and application.

Biologically and environmentally, nitrate can be reduced to nitrite by bacteria in soil and water. In animals, nitrite can be further transformed to reactive nitrogen species, including nitric oxide, which participates in signaling pathways. Excessive nitrate or nitrite intake can pose health risks, including methemoglobinemia in humans and concerns about nitrosamine formation in foods; therefore regulatory guidelines monitor exposure in drinking water and food products.

See also: nitrate, nitrite.