Used as a stable isotope-labeled internal standard in mass spectrometry and metabolic studies to accurately quantify decanoic acid and related fatty acids in biological samples. Its deuterated structure allows clear differentiation from non-labeled compounds during analytical testing. Commonly applied in pharmacokinetic studies, lipidomics, and metabolic pathway tracing where precise measurement is critical. Also utilized in deuterium tracing experiments to study fatty acid metabolism and oxidation processes in vivo and in vitro.