Used primarily as a stable isotope-labeled internal standard in analytical chemistry, especially in mass spectrometry and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Enables accurate quantification and detection of olaquindox residues in animal feed, food, and biological samples by providing a reference with similar chemical behavior but distinct mass. Commonly applied in food safety monitoring, veterinary drug residue analysis, and pharmacokinetic studies to ensure regulatory compliance and assess potential health risks.