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 organophosphorus compounds in environmental samples, industrial effluents, and chemical process streams. Commonly applied in quality control and regulatory testing to monitor levels of plasticizers, flame retardants, and extractants in water, soil, and air. Also used in nuclear fuel processing to standardize measurements of solvent extraction efficiency.