Used as a deuterated internal standard in analytical chemistry, particularly in mass spectrometry and gas chromatography, to accurately quantify dicyclohexyl phthalate and related phthalates in environmental and biological samples. Its stable isotope labeling (deuterium) allows for differentiation from non-labeled compounds, improving measurement precision and reliability. Commonly applied in studies monitoring plasticizer degradation, exposure assessment, and contamination in polymers, soils, and wastewater.