Used as a reference standard in analytical chemistry for the calibration of instruments such as gas chromatographs (GC) and mass spectrometers (MS). Ensures accurate quantification and detection of tributyl phosphate in environmental samples, industrial effluents, and nuclear fuel processing streams. Also employed in quality control for solvent extraction processes, where tributyl phosphate acts as a key extractant in separation of metals like uranium and plutonium in nuclear reprocessing. Helps maintain consistency and reliability in testing procedures across laboratories.