Rapid confirmation/quantitation of cocaine and benzoylecgonine in urine utilizing high performance liquid chromatography and tandem mass spectrometry

A rapid, but sensitive and selective method for confirmation and quantitati on of benzoylecgonine (BZE) and cocaine (COC) in urine by fast-gradient liq uid chromatography/tandem mass spectrometry (LC/MS/MS) is described. The ch romatographic separation was performed on a reversed phase column employing fast-gradient techniques. Matrix prepared standards, blanks, and QC's were filtered then aliquots were transferred into a 96 well plate. Injection vo lumes of 25 mu L were made onto the analytical column, with the flow divert ed from the atmospheric pressure ionization source for the first 0.5 min of the analysis. Simultaneous multiple reaction monitoring (MRM) of three dis crete transitions for each compound were used to identify BZE and COG. Quan titation was achieved utilizing the most prominent parent-daughter transiti on and internal standard calibration techniques. The coefficients of variat ion (CV) for the analysis of these drugs ranged from 0.6% to 6.8% at a conc entration of 150 ng/mL (n = 155). This method suggests that fast-gradient L C/MS/MS may be suitable for routine confirmation of immunoassay cocaine-pos itive samples. (C) 2000 American Society for Mass Spectrometry.