Used as an internal standard in mass spectrometry and gas chromatography for the accurate quantification of polycyclic aromatic hydrocarbons (PAHs) in environmental and biological samples. Its deuterated structure provides a distinct mass shift, allowing clear differentiation from non-labeled analogs during analysis. Commonly applied in studies monitoring PAH contamination in soil, water, and air, as well as in metabolic and toxicological research to track the fate of aromatic compounds. Its stability and consistent behavior in analytical systems enhance measurement precision and reliability.