Sodium nitrite-15N is widely used in research and analytical chemistry as a stable isotope-labeled compound. It serves as a tracer in studies involving nitrogen metabolism, helping to track and understand biochemical pathways in plants, animals, and microorganisms. In environmental science, it is employed to investigate nitrogen cycling processes, such as nitrification and denitrification, in soil and water systems. Additionally, it is utilized in medical research to study the role of nitrite in physiological processes, including its effects on blood flow and oxygen delivery. Its isotopic labeling allows for precise detection and quantification in complex biological and environmental samples.