title: Determination of verapamil in human plasma by mass fragmentography using stable isotope-labelled verapamil as internal standard.
abstract: In the present investigation a mass fragmentographic procedure for the quantitative determination of verapamil in human plasma was developed which makes use of the principle of mass spectrometry and of isotopic dilution: a known amount of isotopically labelled standard ([13C, 2H2]-verapamil) is added to the plasma sample. After an effective extraction procedure the ratio of the main fragments of verapamil (m/e 303) and the labelled standard (m/e 306) is measured by mass fragmentography. The lower limit of detection is at 1 ng/ml for plasma and at 10 pg/injection for pure verapamil. The precision was found to be between 3.4% and 14.4%, depending on the range (32.7 ng/ml and 2.2 ng/ml, resp.) of the concentration of verapamil in plasma.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D008433:Mathematics; D014700:Verapamil / Q000097:blood*
chemical_list: D014700:Verapamil