Used as a stable isotope-labeled internal standard in analytical chemistry, particularly in mass spectrometry and liquid chromatography-tandem mass spectrometry (LC-MS/MS). It aids in the accurate quantification of Sudan I, an illegal azo dye, in food products, spices, and consumer goods. Due to its deuterated structure, it behaves similarly to Sudan I during extraction and analysis but can be distinguished by the mass detector, enabling precise measurement and validation of test results. Commonly applied in food safety and regulatory testing to detect adulteration and ensure compliance with health standards.