Used as a stable isotope-labeled internal standard in mass spectrometry and gas chromatography for the detection and quantification of acetaldehyde in biological samples, environmental analysis, and metabolic studies. Its deuterated structure allows for clear differentiation from endogenous acetaldehyde, improving analytical accuracy. Also employed in kinetic and mechanistic studies to trace metabolic pathways, particularly in alcohol metabolism research. Suitable for use in studies involving isotopic labeling due to its chemical similarity to non-labeled acetaldehyde.