Used as a deuterated internal standard in analytical chemistry, particularly in mass spectrometry and gas chromatography, to accurately quantify trace levels of polycyclic aromatic hydrocarbons (PAHs) in environmental and biological samples. Its stable isotope labeling (d12) allows for clear differentiation from non-labeled compounds, improving measurement precision and reliability. Commonly applied in monitoring pollution, studying metabolic pathways of PAHs, and validating analytical methods for regulatory compliance.