Used as a stable isotope-labeled internal standard in analytical chemistry, particularly in mass spectrometry-based assays. It aids in the accurate quantification of unlabeled analogs in environmental and biological samples by providing a reference with nearly identical chemical behavior but distinct mass detection. Commonly applied in pesticide metabolism studies and residue analysis due to its structural similarity to phenylurea herbicides. Its deuterated methyl and methoxy groups enhance detection sensitivity and reduce background interference.