Arachidonic Acid-d11 is widely used as an internal standard in mass spectrometry for the quantification of arachidonic acid and its metabolites in biological samples. Its deuterated structure ensures accurate and reliable measurements by providing a distinct mass signature that differentiates it from the endogenous arachidonic acid. This application is crucial in research studies focused on understanding inflammation, lipid metabolism, and eicosanoid signaling pathways. Additionally, it aids in drug development and clinical diagnostics by enabling precise analysis of lipid profiles in complex matrices such as blood, tissues, and cell cultures.