A method is described for the determination of abanoquil in human blood. The method is based on high-performance liquid chromatography(HPLC)/atmospheric pressure positive ion chemical ionization mass spectrometry, using (H-2(3))abanoquil as internal standard. Multiple reaction monitoring is employed for selectivity and sensitivity, which enables quantification over the range 10-500 pg ml-1 with acceptable precision and accuracy. This assay methodology illustrates the versatility of atmospheric pressure ionization/tandem mass spectrometry, in conjunction with HPLC, for the separation and quantification of drugs in the subnanogram per millilitre range.
