title: Determination of 1-beta-D-arabinofuranosylcytosine and 1-beta-D-arabinofuranosyluracil in human plasma by high-performance liquid chromatography.
abstract: A method is described for the determination of 1-beta-D-arabinofuranosylcytosine (Ara-C) and its metabolite 1-beta-D-arabinofuranosyluracil (Ara-U) in human plasma. After deproteinization of the plasma sample, separation is performed by reversed-phase liquid chromatography. For Ara-C concentrations exceeding 0.05 mg/l and for Ara-U concentrations exceeding 1 mg/l, injection volumes of 100 microliter are applied. For lower concentrations an injection volume of 500 microliter is used. Ara-C is detected at 280 nm with a lowest detection limit of 0.002 mg/l in plasma. Ara-U is detected at 264 nm with a lowest detection limit varying from 0.01 to 0.1 mg/l in plasma. This variation is caused by an unknown substance with the same elution properties as Ara-U and which appears to be present in plasma in variable concentrations. The coefficient of variation of the whole procedure is about 6% for Ara-C concentrations above 0.005 mg/l and for Ara-U concentrations above 0.1 mg/l. For lower concentrations the coefficient of variation is about 14%.
mesh_terms: D001086:Arabinofuranosyluracil / Q000097:blood* / Q000627:therapeutic use; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003561:Cytarabine / Q000097:blood* / Q000627:therapeutic use; D006801:Humans; D007938:Leukemia / Q000097:blood / Q000188:drug therapy; D014529:Uridine / Q000031:analogs & derivatives*
chemical_list: D003561:Cytarabine; D001086:Arabinofuranosyluracil; D014529:Uridine