title: Quantitation of tacrolimus in whole blood using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS-MS).
abstract: We describe a multiple reaction monitoring positive ion HPLC/tandem mass spectrometric method for quantification of tacrolimus in human whole blood with online extraction and cleanup. Included in this procedure: API 2000 triple quadrupole mass spectrometer with turbo-ion spray source (Applied Biosystems, Foster City, CA); 10-port diverter/switching valve (Valco, Houston, TX); HPLC system (Agilent Technologies series 1100, Wilmington, DE); 10 mm (C(18)) guard cartridge (Perkin Elmer, Norwalk, CT) used as an extraction column; a Nova-Pak C18 analytical column (2.1 x 150 mm I.D., 4 microm, Waters Corp, Milford, MA); washing solution, methanol: 30 mM ammonium acetate pH 5.1 (80:20); eluting solution, methanol:30 mM ammonium acetate pH 5.1 (97:3); flow rate 0.8 mL/min; and a run-time of 2.8 min. The first and third quadrupoles were set to detect the ammonium adduct ion and a high mass fragment of tacrolimus (m/z 821.5-->768.3), and of an internal standard (ascomycin) (m/z 901.8-->834.4). The lower limit of quantification of this method is 3.75 mg/L. The concentration of drug is determined by comparing peak-area ratios for tacrolimus and internal standard to a standard curve constructed using non-weighted linear through zero regression.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Keri J
authors.initials: KJ
authors.lastname: Donaldson
authors.forename: Leslie M
authors.initials: LM
authors.lastname: Shaw
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D015203:Reproducibility of Results; D016559:Tacrolimus / Q000097:blood*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D016559:Tacrolimus