Used as a stable isotope-labeled internal standard in analytical chemistry, particularly in mass spectrometry and nuclear magnetic resonance (NMR) studies to track and quantify cyanuric acid in environmental samples, such as swimming pools and wastewater. Its labeled carbon structure allows researchers to distinguish it from naturally occurring cyanuric acid, improving accuracy in detection and measurement. It is also employed in metabolic and degradation studies to understand the behavior of cyanuric acid in biological and ecological systems.