Detection methods of ammonia nitrogen in water: A review

Ammonia nitrogen (ammonia or ammonium) is widely present in natural waters and can significantly affect aquatic flora and fauna. It plays an extremely important role in human production and health as well as ecosystem stability. Many detection methods, including spectrophotometric methods and ion-selective electrodes, have been developed for the analysis of ammonia nitrogen in water. Herein, recent developments in optical detection, electrochemical detection, and biological enzyme detection systems for aqueous ammonia nitrogen detection are reviewed. The detection principles are described, advantages and disadvantages of each method are highlighted, and reagent optimization, technological innovations, and novel sensitive materials to improve the detection limits and reduce interference are discussed in detail. For oceanographers and related researchers, this review will serve as a reference of promising detection techniques.