High resolution gas chromatography/mass spectrometric characterization of urinary metabolites of N,N-diethyl-m-toluamide (DEET) in man

Studies of the pharmacology and toxicology of the popular insect repellant, N,N-diethyl-m-toluamide (DEET), have largely been done in animal models using radioactive tracing without the structural elucidation of its metabolites. This paper describes a high resolution gas chromatography/mass spectrometry (GC/MS) technique and reports the results of the preliminary characterization of the metabolites of DEET in the urine of a 30-year-old man who had been exposed to DEET contained in a commercial product. The metabolites were extracted and separated with an OV-101 glass capillary column, 30 m × 0.3 mm, and mass spectrometric elucidations were carried out with both Electron Impact (EI) and Chemical Ionization-Methane (MCI) modes. Oxidation of the benzylic moiety and hydroxylation of the sidechain of DEET molecules appeared to be the predominate routes of metabolism in man. The artifacts were also proposed.