Gas chromatography of simple phenols in biological fluids

Acid hydrolysis of phenol conjugates in urine by concentrated H3PO4 followed by extraction of phenols with n-hexane and their acetylation before gas chromatography on columns packed with OV-1 or OV-17 is described. The sensitivity of the method is sufficient to monitor normal levels of phenol and p-cresol or phenol and o-cresol after exposure to benzene or toluene vapours. The detection limit is 1 mg/l. The method can also be used to diagnose acute oral intoxication by phenol or cresols and to estimate its significance in clinical or forensic toxicology. Normal urine levels of phenols and those in different cases of human intoxication are evaluated.