Used as a stable isotope-labeled internal standard in mass spectrometry and metabolic studies to accurately quantify palmitic acid and related lipid species in biological samples. Its deuterated form allows for differentiation from endogenous palmitic acid, minimizing interference and improving measurement precision. Commonly applied in lipidomics, pharmacokinetic studies, and investigations of fatty acid metabolism, including lipid biosynthesis, oxidation, and signaling pathways. Also utilized in tracer experiments to track metabolic flux in cells, tissues, or whole organisms without altering the chemical behavior of the parent compound.