Validation of an LC-MS assay for the quantification of the enantiomers of Org 4428 in human plasma.

Abstract A sensitive and selective liquid chromatographic mass spectrometric assay has been validated for the quantification of Org 4428 enantiomers in human plasma. The assay employs n -hexane extraction from alkalinized plasma, separation on a narrow-bore enantioselective normal phase Chiralpak AD column and APCI MS-MS detection. The lower limit of quantification is 0.5 ng ml −1 plasma for the individual enantiomers.