Ammonium citrate is an organic compound with the chemical formula (NH4)3C6H5O7. It is a white or colorless crystal that usually exists in a hydrated form, such as (NH4)3C6H5O7·5H2O. Ammonium citrate is a water-soluble salt prepared by the reaction of citric acid and ammonia, which has a strong buffering capacity, so it has a wide range of applications in laboratories and industries.

Ammonium citrate is used in the food industry as a buffer, acidity regulator, and preservative. It can also be used as an emulsifier and stabilizer for food, helping to maintain the texture of food and extend shelf life. In addition, ammonium citrate is also used in the pharmaceutical industry as an ingredient or adjuvant in drugs, as well as in the preparation of buffer solutions.

In laboratories, ammonium citrate is often used as a chemical analysis reagent, especially in coordination chemistry and in the precipitation and separation of metal ions. It is also a good complexing agent and is able to form stable complexes with a variety of metal ions, so it is very useful in metal ion analysis.

Ammonium citrate is also used in the production of detergents and detergents due to its ability to react with calcium and magnesium ions in hard water to form soluble complexes, thereby reducing the formation of limescale.