Gas chromatography-chemical ionization mass spectrometry of cocaine and its metabolites in biological fluids.

A gas chromatographic-chemical ionization mass spectrometric (GC-CIMS) method is described for the determination of cocaine, benzoylecgonine, and norcocaine. The procedure uses stable isotopes as internal standards and a mixture of methane-ammonia as chemical ionization reagent gas. Run-to-run and within-run coefficients of variation (%) are less than 10% and the method has a sensitivity of less than 5 ng/mL from 1 mL or 1 gram of sample. The procedure has been applied to a number of cases involving cocaine intoxication and analytical data from these are described.