title: Quantitative analysis of EO9 (apaziquone) and its metabolite EO5a in human plasma by high-performance liquid chromatography under basic conditions coupled to electrospray tandem mass spectrometry.
abstract: A sensitive and specific LC-MS/MS assay for the quantitative determination of EO9 and its metabolite EO5a is presented. A 200-microl human plasma aliquot was spiked with a mixture of deuterated internal standards EO9-d3 and EO5a-d4 and extracted with 1.25 ml ethyl acetate. Dried extracts were reconstituted in 0.1 M ammonium acetate-methanol (7 : 3, v/v) and 25 microl-volumes were injected into the HPLC system. Separation was achieved on a 150 x 2.1 mm C18 column using an alkaline eluent (1 mM ammonium hydroxide-methanol (gradient system)). Detection was performed by positive ion electrospray followed by tandem mass spectrometry. The assay quantifies a range from 5 to 2500 ng/ml for EO9 and from 10 to 2500 ng/ml EO5a using 200 microl of human plasma samples. Validation results demonstrate that EO9 and EO5a concentrations can be accurately and precisely quantified in human plasma. This assay will be used to support clinical pharmacologic studies with EO9.
authors.affiliation: Department of Pharmacy and Pharmacology, Slotervaart Hospital, Louwesweg 6, 1066 EC Amsterdam, The Netherlands. apliv@slz.nl
authors.forename: Liia D
authors.initials: LD
authors.lastname: Vainchtein
authors.forename: Hilde
authors.initials: H
authors.lastname: Rosing
authors.forename: Dorla
authors.initials: D
authors.lastname: Mirejovsky
authors.forename: Van
authors.initials: V
authors.lastname: Huynh
authors.forename: Luigi
authors.initials: L
authors.lastname: Lenaz
authors.forename: Michel J X
authors.initials: MJ
authors.lastname: Hillebrand
authors.forename: Jan H M
authors.initials: JH
authors.lastname: Schellens
authors.forename: Jos H
authors.initials: JH
authors.lastname: Beijnen
mesh_terms: D018906:Antineoplastic Agents, Alkylating / Q000097:blood*; D001388:Aziridines / Q000097:blood*; D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D045563:Indolequinones / Q000097:blood*; D011786:Quality Control; D012015:Reference Standards; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D018906:Antineoplastic Agents, Alkylating; D001388:Aziridines; D045563:Indolequinones; C082259:EO 5A; C060817:apaziquone