Used primarily as a labeled internal standard in mass spectrometry and gas chromatography for the detection and quantification of naphthalene derivatives in environmental and biological samples. Its deuterated structure allows for clear differentiation from non-labeled compounds during analysis, improving accuracy in trace-level measurements. Commonly applied in studies involving polycyclic aromatic hydrocarbon (PAH) metabolism, environmental contamination monitoring, and isotopic tracer experiments. Due to its stability and distinct mass signature, it aids in validating analytical methods and ensuring reliable data in research and regulatory testing.