Used as a deuterated internal standard in analytical chemistry, particularly in mass spectrometry and gas chromatography, to accurately quantify trace levels of diisobutyl phthalate in environmental, biological, and industrial samples. Its stable isotope labeling allows for precise differentiation from non-labeled compounds, improving measurement accuracy and reliability. Commonly applied in studies monitoring phthalate contamination in water, soil, and consumer products, as well as in metabolic and toxicokinetic research.