title: Stable and sensitive method for the simultaneous determination of N5-methyltetrahydrofolate, leucovorin, methotrexate and 7-hydroxymethotrexate in biological fluids.
abstract: A high-performance liquid chromatographic method for the determination of N5-methyltetrahydrofolic acid, leucovorin, methotrexate and 7-hydroxymethotrexate in plasma and liquor samples is presented. Gradient elution is used to increase the sensitivity. Four sample preparation methods were compared with respect to the stability of the injectable sample. Samples can be pretreated with a simple deproteinization method. For enhanced selectivity a solid-phase extraction procedure is described.
authors: Department of Clinical Chemistry, Netherlands Cancer Institute, Amsterdam.
authors: O
authors: O
authors: van Tellingen
authors: H R
authors: HR
authors: van der Woude
authors: J H
authors: JH
authors: Beijnen
authors: C J
authors: CJ
authors: van Beers
authors: W J
authors: WJ
authors: Nooyen
mesh_terms: D002851:Chromatography, High Pressure Liquid; D006801:Humans; D002955:Leucovorin / Q000097:blood / Q000134:cerebrospinal fluid / Q000378:metabolism*; D008727:Methotrexate / Q000031:analogs & derivatives* / Q000097:blood / Q000134:cerebrospinal fluid / Q000378:metabolism*; D013056:Spectrophotometry, Ultraviolet; D013763:Tetrahydrofolates / Q000097:blood / Q000134:cerebrospinal fluid / Q000378:metabolism*
chemical_list: D013763:Tetrahydrofolates; D002955:Leucovorin; C005984:5-methyltetrahydrofolate; C011864:7-hydroxymethotrexate; D008727:Methotrexate