Furan D4 is widely used as a stable isotope-labeled internal standard in analytical chemistry, particularly in mass spectrometry. It aids in the accurate quantification of furan and related compounds in various samples, such as food, beverages, and environmental matrices. Its application ensures precision and reliability in detecting trace levels of furan, which is important for assessing potential health risks associated with exposure to this compound. Additionally, Furan D4 is utilized in research studies to understand the metabolism and distribution of furan in biological systems, providing valuable insights into its toxicological effects.