title: A validated LC-MS/MS method for rapid determination of methotrexate in human saliva and its application to an excretion evaluation study.
abstract: A sensitive and simple method for the methotrexate quantification was developed using aminopterin as internal standard. Methotrexate is an anticancer agent that is widely used in a variety of human cancers including primary central nervous system lymphoma. The compound was quantified by liquid-chromatography coupled to electrospray ionization (positive ion-mode) low-energy collision dissociation-tandem mass spectrometry. Quantitative detection was by multiple reaction monitoring of the transitions of the [M+H]+ ion of MTX to its common product ion at m/z 308.4 and of aminopterin at m/z 441.2→m/z 294.0. The method demonstrated linearity over at least three orders of magnitude and had a detection limit of 1ng/ml for methotrexate. A run time of less than 8.0min for each sample made it possible to analyze a large number of human saliva samples per day. Application of this procedure was demonstrated to a saliva excretion study of methotrexate on the samples obtained after an intravenously administration of 1mg/kg/dose of methotrexate to six patients with acute lymphoblastic leukemia.
authors.affiliation: Lomonosov Moscow State University, Department of Chemistry, Moscow, Russia. Electronic address: rodin@analyt.chem.msu.ru.
authors.forename: Igor
authors.initials: I
authors.lastname: Rodin
authors.forename: Arkady
authors.initials: A
authors.lastname: Braun
authors.forename: Andrey
authors.initials: A
authors.lastname: Stavrianidi
authors.forename: Oleg
authors.initials: O
authors.lastname: Shpigun
mesh_terms: D000328:Adult; D000964:Antimetabolites, Antineoplastic / Q000032:analysis* / Q000737:chemistry / Q000493:pharmacokinetics / Q000627:therapeutic use; D002853:Chromatography, Liquid / Q000379:methods*; D004355:Drug Stability; D005260:Female; D006801:Humans; D057230:Limit of Detection; D008297:Male; D008727:Methotrexate / Q000032:analysis* / Q000737:chemistry / Q000493:pharmacokinetics / Q000627:therapeutic use; D008875:Middle Aged; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy / Q000378:metabolism; D015203:Reproducibility of Results; D012463:Saliva / Q000737:chemistry* / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000964:Antimetabolites, Antineoplastic; D008727:Methotrexate
keywords: Liquid chromatography; Methotrexate; Saliva excretion study; Tandem mass spectrometry