Used as a stable isotope-labeled internal standard in mass spectrometry and analytical chemistry for quantifying amines and amine-containing compounds. Its deuterated ethyl group enhances detection specificity by providing a distinct mass shift, improving accuracy in biological, environmental, and pharmaceutical sample analysis. Commonly applied in metabolic studies and drug development where precise tracking of amine metabolites is required. Also serves as a reagent in synthesis of deuterated compounds to study reaction mechanisms or improve pharmacokinetic properties of active pharmaceutical ingredients.