Nitrátot

Nitrátot, or nitrates, are chemical compounds containing the nitrate ion, NO3−. They form salts with various cations, such as sodium nitrate (NaNO3), potassium nitrate (KNO3), calcium nitrate (Ca(NO3)2, and ammonium nitrate (NH4NO3). In organic chemistry, nitrate esters are organic compounds in which the nitrate group is bound to an alkyl or aryl moiety, such as ethyl nitrate. The nitrate ion is the conjugate base of nitric acid and nitrogen in nitrates is in the +5 oxidation state.

Nitrates occur naturally in soils and groundwater as a product of the microbial oxidation of ammonium. They are also produced industrially by neutralizing nitric acid with bases or derived from nitrification processes in soils and waters. Agricultural activities, fertilizer use, and waste mobilization influence nitrate levels in the environment.

Nitrate salts have widespread uses. They are important nitrogen fertilizers that support plant growth. Some nitrates are used in pyrotechnics and explosives, most notably ammonium nitrate. In the food industry, nitrates and related nitrites are used as curing agents and preservatives in processed meats, with the nitrate form often acting as a reservoir that can convert to nitrite.

Environmental and health considerations are significant. Excess nitrates entering water bodies can contribute to eutrophication, algal blooms, and oxygen depletion. In drinking water, high nitrate levels pose health risks, particularly to infants, where methemoglobinemia can occur. Regulatory standards for nitrate content vary by country, commonly expressed as nitrate-nitrogen (NO3−-N) or nitrate (NO3−) concentrations.

Chemically, the nitrate ion is typically highly soluble in water and exhibits resonance that stabilizes the structure. Under anaerobic conditions, denitrification can reduce nitrates to nitrogen gas, returning nitrogen to the atmosphere as part of the nitrogen cycle. Some nitrate salts are also explosive precursors, requiring careful handling and storage.