Used as an analytical reference standard in environmental testing to detect and quantify pesticide residues, particularly in soil, water, and agricultural samples. It serves as a metabolite marker for fenitrothion degradation studies, helping assess the environmental fate and breakdown pathways of the parent pesticide. Also employed in toxicological research to evaluate the metabolic activation and cholinesterase-inhibiting effects of organophosphate compounds. Commonly used in chromatographic and mass spectrometry methods for calibration and validation of analytical procedures.