Evaluation of ticlopidine in human serum and plaque by liquid chromatography/atmospheric pressure chemical ionization mass spectrometry

A method based on liquid chromatography with atmospheric pressure positive-ion chemical ionization detection in the presence of ammonium acetate and formic acid for the determination of ticlopidine in human serum and plaque has been developed. The drug was extracted from the biological matrices using a single solid-phase C-18 cartridge. The protonated molecule with substantial fragmentation was obtained by using this ionization technique. The ion signals in different solvents were evaluated. The chromatographic run time was about 10 min and the method had sufficient sensitivity, precision, accuracy and selectivity for the analysis of clinical sample containing ticlopidine at concentrations down to 1 ng ml−1 for serum samples and 1 ng g−1 for plaque samples. The limits of detection (signal : noise=3) were 300 pg ml−1 and 330 pg g−1, respectively.