LC-MS DETERMINATION OF P-(1-DIMETHYL AMINO ETHYLAMINO) ANILINE IN HUMAN PLASMA

A sensitive and selective liquid chromatography-mass spectrometry (LC-MS) method was developed and validated for the determination of p-(1-dimethyl amino ethylamino) aniline (dADT), a metabolite of Tribendimidine, in human plasma. The analyte was separated on a Hypersil C18 column (250 × 4.6mm internal diameter, 5 1m) by isocratic elution with 10mM ammonium acetate (containing 0.1% triethylamine)-acetonitrile (20:80, v/v) at a flow rate of 1mL min -1 and measured by electrospray ionization source in positive selective ion monitoring mode at m/z (mass to charge ratio) 178. The weighted (1 /x 2) calibration curve was linear within a concentration range of 0.5-1,000ng/mL and displayed a correlation coefficient (r) of 0.9996. The lower limit of quantification was determined to be at 0.5ng/mL. The inter- and intra-day precisions (% RSD) were less than 8% and the extraction recoveries ranged from 84.21 to 85.20%. The developed method was successfully applied to the determination of dADT in human plasma as part of a clinical pharmacokinetic study.