Used as a deuterated internal standard in analytical chemistry, particularly in mass spectrometry and gas chromatography, to accurately quantify phthalate levels in environmental and biological samples. Its stable isotope labeling allows for precise tracking and differentiation from non-labeled compounds, improving measurement accuracy in studies related to plasticizer exposure and metabolic research. Also employed in degradation studies to monitor the fate of phthalates in ecosystems without interference from endogenous sources.