GAS-CHROMATOGRAPHIC DETERMINATION OF 2-DECHLOROETHYLIFOSFAMIDE AND 3-DECHLOROETHYLIFOSFAMIDE IN PLASMA AND URINE

The metabolic oxidation of one of the chloroethyl groups of the antitumour drug ifosfamide leads to the formation of the inactive metabolites 2- and 3-dechloroethylifosfamide together with the neurotoxic metabolite chloroacetaldehyde. A very sensitive capillary gas chromatographic method, requiring only 50 mul of plasma or urine, has been developed to measure the amounts of the drug and the two inactive metabolites in a single run. Calibration curves were linear (r > 0.999) in the concentration ranges from 50 ng/ml to 100 mug/ml in plasma and from 100 ng/ml to 1 mg/ml in urine.