Used as a stable isotope-labeled internal standard in mass spectrometry for accurate quantification of fatty acid methyl esters in biological and environmental samples. Its deuterated structure allows clear differentiation from non-labeled compounds, improving measurement precision in lipid profiling, metabolic studies, and gas chromatography-mass spectrometry (GC-MS) analysis. Commonly applied in research involving lipid metabolism, biomarker discovery, and fatty acid composition in tissues, oils, and biofuels.