Characterization of two metabolites of prethcamide by gas chromatography and mass spectrometry

Crotethamide and cropropamide, both components of the respiratory stimulant prethcamide, are metabolized in humans by demethylation of the [(dimethylamino)-carbonyl]-propyl moiety. The resulting metabolites are characterized by gas chromatography-mass spectrometry of urinary extracts. The use of HCl to prevent losses by volatilization during the evaporation step, combined with methanol as solvent, complicates gas liquid chromatographic analysis of prethcamide. The resulting artifacts are identified.