title: Rapid and sensitive liquid chromatography-tandem mass spectrometry method for the determination of leuprolide in human serum.
abstract: Leuprolide is a synthetic nonapeptide that has two basic amino acids, arginine and histidine, in its structure. By selection of an appropriate analytical column and optimizing the mobile phase composition, an improved analytical method has been developed and validated to determine leuprolide concentrations in human serum. After methanol-induced protein precipitation of serum samples and Oasis HLB cartridge solid-phase extraction, leuprolide and an internal standard (alarelin) were analyzed on a C(18) column interfaced with a triple quadrupole tandem mass spectrometer with positive electrospray ionization. The mobile phase consisted of acetonitrile-water-propionic acid (20:80:0.05). The analyte and internal standard were both detected in the selective reaction monitoring mode. The method exhibited a linear range of 0.018-45.2ng/mL for leuprolide. The intra- and inter-assay precisions were 11.5% or less relative standard deviation (R.S.D.), and accuracy was within +/-2.8% relative error (RE). The lower limit of quantification (LLOQ) was identifiable and reproducible at 0.018ng/mL, with acceptable precision and accuracy. The validated LC-MS/MS method was tested to a clinical pharmacokinetic study of leuprolide after a single subcutaneous injection of 1mg leuprolide acetate in healthy male Chinese volunteers.
authors.affiliation: Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 646 Songtao Road, Shanghai 201203, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhan
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Chen
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Zhao
authors.forename: Dafang
authors.initials: D
authors.lastname: Zhong
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D004355:Drug Stability; D006801:Humans; D016729:Leuprolide / Q000097:blood* / Q000493:pharmacokinetics; D016014:Linear Models; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D016729:Leuprolide