title: Microscale high-performance liquid chromatography-electrospray tandem mass spectrometry assay for cyclosporin A in blood.
abstract: To facilitate quantitative analysis of cyclosporin A in low volume blood samples we developed a sensitive and specific microscale reversed-phase HPLC-electrospray tandem mass spectrometry assay. Blood samples (100 microl) were prepared by acetonitrile precipitation and C18 solid-phase extraction. Detection was by multiple-reactant monitoring. The method was linear over the range 5-1000 microg/l (r> or =0.997) with accuracy between 95.4 and 102.0% over this range. Total imprecision was 11.1% at 10 microg/l and 2.8% at 800 microg/l. Absolute recovery of cyclosporin A and internal standard was 72.5 and 73.3%, respectively. When this method was evaluated against a conventional HPLC with UV detection, in patient samples, they were interchangeable (y=0.988x + 10.0, r=0.996). This HPLC-ESI-MS-MS method will be applicable to therapeutic monitoring in paediatric transplant patients and multiple point pharmacokinetic studies in animals and humans.
authors.affiliation: Department of Clinical Pharmacology, Princess Alexandra Hospital, Brisbane, QLD, Australia.
authors.forename: P J
authors.initials: PJ
authors.lastname: Taylor
authors.forename: C E
authors.initials: CE
authors.lastname: Jones
authors.forename: P T
authors.initials: PT
authors.lastname: Martin
authors.forename: S V
authors.initials: SV
authors.lastname: Lynch
authors.forename: A G
authors.initials: AG
authors.lastname: Johnson
authors.forename: S M
authors.initials: SM
authors.lastname: Pond
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D016572:Cyclosporine / Q000097:blood*; D006801:Humans; D013058:Mass Spectrometry; D008832:Microchemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet
chemical_list: D016572:Cyclosporine