Ammonium (NH₄⁺) and ammonia (NH₃) in aquatic ecosystems are of great interest to environmental scientists because they can be used to study the nitrogen cycle and as water quality indicators. Analytical separation methods developed in recent decades have been used widely to determine NH₄⁺ and NH₃ in aqueous solutions. This review presents an overview of state-of-the-art separation methods and analytical techniques for determining NH₃/NH₄⁺ in natural water, including chromatographic methods, electrophoretic methods, extraction methods, membrane-based gas diffusion methods, membraneless gas diffusion methods, passive sampling methods, and paper-based analytical methods. Common detection techniques that can be used in conjunction with particular separation methods are described, phase-transfer strategies (liquid-liquid, liquid-solid, liquid-membrane-liquid, and liquid-gas-liquid methods) are highlighted, and the strengths and weaknesses of the separation methods are discussed. The outlook, challenges, and expected future developments in the field of separation methods for determining NH₄⁺ and NH₃ in natural water are presented.

水生生态系统中的铵（NH ₄ ⁺）和氨（NH ₃）对环境科学家非常感兴趣，因为它们可用于研究氮循环并作为水质指标。近几十年来开发的分析分离方法已广泛用于测定水溶液中的NH ₄ ⁺和NH ₃。这篇综述概述了用于测定NH ₃ / NH ₄ ⁺的最新分离方法和分析技术天然水中的色谱法，包括色谱法，电泳法，提取法，膜基气体扩散法，无膜气体扩散法，被动采样法和纸基分析法。描述了可以与特定分离方法结合使用的常见检测技术，重点介绍了相转移策略（液-液，液-固，液膜-液和液-气-液方法），并指出了其优势和优势。讨论了分离方法的弱点。介绍了用于确定天然水中NH ₄ ⁺和NH ₃的分离方法领域的前景，挑战和预期的未来发展。