title: Determination of the two mononitrate metabolites of isosorbide dinitrate in human plasma and urine by gas chromatography with electron-capture detection.
abstract: This paper describes a sensitive method for the determination of 2-isosorbide mononitrate and 5-isosorbide mononitrate as metabolites of isosorbide dinitrate at concentrations down to 2 ng/ml of 2-isosorbide mononitrate in both plasma and urine, and 5 ng/ml and 10 ng/ml of 5-isosorbide mononitrate in plasma and urine, respectively. The two mononitrate metabolites are extracted at basic pH into ethyl acetate, which is then evaporated to dryness. The residue is dissolved in a basic aqueous solution, which is washed with heptane and then re-extracted into ethyl acetate. The metabolites are quantitated by gas chromatography, using a 63Ni electron-capture detector. Conjugates of 2- and 5-isosorbide mononitrate are determined in urine after enzymatic hydrolysis.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D002849:Chromatography, Gas / Q000379:methods; D006801:Humans; D006868:Hydrolysis; D007548:Isosorbide Dinitrate / Q000031:analogs & derivatives* / Q000032:analysis / Q000097:blood / Q000652:urine; D008297:Male; D013997:Time Factors
chemical_list: C030398:isosorbide-2-mononitrate; D007548:Isosorbide Dinitrate; C030397:isosorbide-5-mononitrate