Application of exact mass ms in bioanalysis discovery quantitation with uplc and xevo qtof ms

The quantification of candidate pharmaceuticals and/or their metabolites in biological fluids plays a key role in drug discovery. The information generated is used to determine key pharmacokinetics parameters such as clearance, half-life, Tmax, and bioavailability. During discovery ADME studies the metabolic fate of the molecule is determined as well as its pharmacokinetics. Currently this involves using two analytical instruments: one to provide the quantitative information and one for the qualitative analysis. Quantitative information is normally derived from a tandem quadrupole instrument due to sensitivity; qualitative data is gathered either from an ion trap or quadrupole time-of-flight MS (QTof) instrument. This need for multiple instruments and analytical runs results in reduced productivity and increased instrument capital costs. QTof technology is well-recognized as the platform of choice for exact mass MS/MS structural elucidation.1-3 However, its use in quantitative DMPK studies has yet to be fully exploited. In this application note, we present the use of a high-sensitivity QTof mass spectrometer coupled with UltraPerformance LC® (UPLC®) separation technology for the quantitative analysis of a model candidate pharmaceutical at the levels of sensitivity required for drug discovery.