Joanne Mather, Paul D. Rainville, Warren B. Potts III, Norman W. Smith and Robert S. Plumb
A rapid, specific, assay was developed for the benzodiapine alprazolam in rat plasma using sub 2 µm particle LC and tandem quadrupole MS/MS. The limit of quantification using protein precipitation was determined to 10 pg/mL, where as the limit of quantification using solid phase extraction was determined to be 1.0 pg/mL. The assay was optimised for throughput and resolution of the analyte of interest from the hydroxy metabolite. During the method development process the plasma matrix signal was monitored, for lipids and other endogenous metabolites, to maximize signal response and minimize ion suppression.