Used as a stable isotope-labeled internal standard in gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) for quantifying fatty acids and long-chain hydrocarbons in biological and environmental samples. Its isotopic labeling at specific carbon positions (C-2 and C-13) allows precise tracking of metabolic pathways and degradation processes in studies involving lipid metabolism, microbial transformation, and environmental fate of alkanes. Due to its structural similarity to natural hexadecane, it behaves nearly identically in analytical systems, improving accuracy and reproducibility in quantitative analysis.