AMOZ-d5 is a deuterated analog (d5 indicates five deuterium atoms replacing hydrogen) primarily used as an internal standard in analytical chemistry for the detection and quantification of AMOZ (3-amino-5-morpholinomethyl-2-oxazolidinone), a key metabolite of the veterinary drug furaltadone, in food products such as meat, seafood, and other animal-derived items. Due to its structural similarity to AMOZ, it plays a crucial role in ensuring accuracy and reliability in mass spectrometry-based methods, such as LC-MS/MS, by compensating for variations in sample preparation and instrument performance. Its application is essential in food safety testing, helping to monitor and enforce regulatory compliance regarding veterinary drug residues.