Used primarily as a derivatization reagent in analytical chemistry, especially in gas chromatography (GC) and mass spectrometry (MS). It introduces a highly fluorinated aromatic group to compounds containing active hydrogen atoms, such as alcohols, phenols, and amines, enhancing their volatility, thermal stability, and detection sensitivity. The pentafluorophenyl group improves electron-capture properties, making derivatized analytes easier to detect using electron capture detectors (ECD) or in negative ion chemical ionization (NICI) mass spectrometry. Commonly applied in environmental analysis, metabolomics, and pesticide residue testing due to its ability to increase selectivity and lower detection limits. Also employed in the synthesis of specialty agrochemicals and pharmaceuticals where fluorinated building blocks are needed to modulate lipophilicity and metabolic stability.