Simultaneous identification of cocaine and benzoylecgonine using solid phase extraction and gas chromatography/mass spectrometry.

A procedure for the simultaneous detection and quantitation of cocaine and benzoylecgonine from urine is described. Using solid phase extraction, cocaine, benzoylecgonine, deuterated cocaine, and deuterated benzoylecgonine (2 internal standards) are extracted from urine. Benzoylecgonine and the deuterated benzoylecgonine are derivatized to their trimethylsilyl esters. The underivatized cocaine and derivatized benzoylecgonine are detected by electron impact mass spectrometry in the selected ion monitoring mode. Both cocaine and benzoylecgonine are detected at concentrations of 50 ng/mL. In addition, the procedure is simple, rapid, and suitable for a large number of specimens.