Used in environmental testing to calibrate analytical instruments for detecting polycyclic aromatic hydrocarbons (PAHs) in soil, water, and air samples. Commonly applied in gas chromatography and high-performance liquid chromatography to quantify PAH contamination. Helps ensure accuracy in monitoring industrial emissions, assessing pollution levels, and complying with regulatory standards. Also used in research studies on the fate and behavior of organic pollutants in ecosystems.