Cyantraniliprole D3 (deuterated cyantraniliprole-d₃) is a stable isotope-labeled internal standard used in liquid chromatography-mass spectrometry (LC-MS/MS) for the accurate quantification of cyantraniliprole residues in agricultural crops, soil, water, food products, and environmental samples. It compensates for matrix effects, extraction losses, and instrument variability, ensuring precise pesticide residue analysis for regulatory compliance, food safety monitoring, and agrochemical research.