Used primarily as a labeled internal standard in analytical chemistry, especially in mass spectrometry and chromatography for the detection and quantification of chloroaniline derivatives in environmental and biological samples. Its deuterated structure allows for clear differentiation from non-labeled compounds, improving accuracy in residue analysis. Also employed in metabolic studies to track reaction pathways and degradation mechanisms of aromatic amines. Due to its isotopic labeling, it helps minimize matrix effects and enhances measurement precision in complex mixtures.