title: Validation of an assay for voriconazole in serum samples using liquid chromatography-tandem mass spectrometry.
abstract: A simple and rapid liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method for the analysis of voriconazole has been developed. For comparison, serum voriconazole was measured using HPLC and bioassay. For the HPLC-MS/MS assay, samples were prepared in a deep-well block by adding 10 microL of serum to 40 microL of 0.1 M zinc sulfate solution. Proteins were precipitated by adding 100 microL acetonitrile containing ketoconazole as internal standard. After vigorous mixing and centrifugation, 3 microL of the supernatant was injected into the HPLC-MS/MS system. An HPLC system was used to elute a C18 cartridge (2 mm x 4 mm) at 0.6 mL/min with a step gradient of 50% to 100% methanol containing 2 mM ammonium acetate and 0.1% (vol/vol) formic acid. The column was maintained at 55 degrees C, and the retention times were voriconazole 1.50 minutes and ketoconazole 1.47 minutes. Cycle time was 3 minutes, injection to injection. The analytes were monitored using a tandem mass spectrometer operated in multiple reaction monitoring mode using the following transitions: voriconazole m/z 350.0 > 224.1 and ketoconazole m/z 531.1 > 489.1. Within- and between-batch CVs were < 5% and < 8%, respectively, over the range 0.38 to 15.3 mg/L. The lower limit of quantification was 0.1 mg/L. Regression analysis showed HPLC-MS/MS = 1.06 +/- 0.02 (HPLC-UV) - 0.07 +/- 0.1, R2 = 0.95, n = 99.
authors.affiliation: Department of Clinical Biochemistry, Wythenshawe Hospital, South Manchester University Hospitals, NHS Trust, Manchester M23 9LT, England, UK. bkeevil@smuht.nwest.nhs.uk
authors.forename: Brian G
authors.initials: BG
authors.lastname: Keevil
authors.forename: Sheila
authors.initials: S
authors.lastname: Newman
authors.forename: Stephen
authors.initials: S
authors.lastname: Lockhart
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Howard
authors.forename: Caroline B
authors.initials: CB
authors.lastname: Moore
authors.forename: David W
authors.initials: DW
authors.lastname: Denning
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D011743:Pyrimidines / Q000097:blood*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D014230:Triazoles / Q000097:blood*; D065819:Voriconazole
chemical_list: D011743:Pyrimidines; D014230:Triazoles; D065819:Voriconazole