title: Quantitative measurement of cyclosporin A in blood by time-of-flight mass spectrometry.
abstract: Analytical methods have been developed for the detection and quantification of cyclosporin A (CsA) in blood using time-of-flight secondary-ion mass spectrometry (TOF-SIMS) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI/TOF-MS). Linear calibration curves were obtained for both methods in the range 25-2000 ng/mL in whole blood. The limit of detection (LOD) and limit of quantification (LOQ) were determined to be 7 and 23 ng/mL, respectively, for the TOF-SIMS method; the LOD and LOQ were 10 and 33 ng/mL, respectively, for the MALDI/TOF-MS method. Coefficients of variation ranged from 3 to 5% for the TOF-SIMS method and from 4 to 8% for the MALDI/TOF-MS method. Blood samples were also analyzed by a nonspecific method, fluorescence polarization immunoassay (FPIA), and by a specific method, high-performance liquid chromatography (HPLC). The TOF-MS results are in good agreement with the HPLC results, but not with the FPIA results. The TOF-MS methods can also provide information about CsA metabolites.
authors.affiliation: Department of Chemistry, University of Pittsburgh, Pennsylvania 15260.
authors.forename: D C
authors.initials: DC
authors.lastname: Muddiman
authors.forename: A I
authors.initials: AI
authors.lastname: Gusev
authors.forename: A
authors.initials: A
authors.lastname: Proctor
authors.forename: D M
authors.initials: DM
authors.lastname: Hercules
authors.forename: R
authors.initials: R
authors.lastname: Venkataramanan
authors.forename: W
authors.initials: W
authors.lastname: Diven
mesh_terms: D002851:Chromatography, High Pressure Liquid; D016572:Cyclosporine / Q000097:blood*; D016231:Fluorescence Polarization Immunoassay; D006801:Humans; D013058:Mass Spectrometry; D016339:Spectrometry, Mass, Fast Atom Bombardment
chemical_list: D016572:Cyclosporine