Used primarily as a reference standard in analytical chemistry for the detection and quantification of naproxen and related metabolites. It serves as a stable analog in mass spectrometry and chromatographic methods, particularly in pharmaceutical and environmental testing. Due to its structural similarity to naproxen esters, it aids in method development for drug metabolism studies and bioavailability assessments. Also employed in research settings to calibrate instruments and validate analytical procedures involving naphthalene-based compounds.