title: [LC-MS/MS method for simultaneous quantification of lopinavir and ritonavir in human plasma].
abstract: A liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method was developed for the determination of lopinavir and ritonavir in human plasma. Analytes were separated from plasma by a combination of alkalinized protein precipitation and liquid-liquid extraction with ethyl acetate. Chromatographic separation was performed on a Agilent ZORBAX Eclipse XDB-C18 column with the mobile phase consisted of methanol-0.1% formic acid in water (80:20). A tandem mass spectrometer equipped with electrospray ionization source was used as detector and operated in the positive ion mode. Quantification was performed using multiple reaction monitoring (MRM) of the transitions m/z 629.6 --> 155.2, m/z 721.4 --> 268.2, and m/z 515.2 --> 276.2 for lopinavir, ritonavir and telmisartan (internal standard), respectively. The method showed a good linearity in a concentration range of 62.5 - 10000 ng mL(-1) for lopinavir, and 12.5 - 2000 ng mL(-1) for ritonavir. The lower limits of quantification were 15 pg mL(-1) and 8 pg mL(-1) for lopinavir and ritonavir, respectively. The intra- and inter-day precision was less than 15% and the absolute recovery was above 75%. This method was selective and rapid, sensitive for investigating blood drug concentrations in clinics.
authors.affiliation: Shanghai Public Health Clinical Center, Shanghai 201508, China.
authors.forename: Ya-min
authors.initials: YM
authors.lastname: Yao
authors.forename: Jian-jun
authors.initials: JJ
authors.lastname: Sun
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Xiao-qian
authors.initials: XQ
authors.lastname: Liu
authors.forename: Hong-zhou
authors.initials: HZ
authors.lastname: Lu
authors.forename: Li-jun
authors.initials: LJ
authors.lastname: Zhang
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D015658:HIV Infections / Q000097:blood; D006801:Humans; D061466:Lopinavir / Q000097:blood*; D019438:Ritonavir / Q000097:blood*; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D061466:Lopinavir; D019438:Ritonavir