title: Quantification of limonin in human urine using solid-phase extraction by LC-MS/MS.
abstract: A highly sensitive liquid chromatography-tandem mass spectrometry method was developed and validated for the determination of limonin in human urine using podophyllotoxin as internal standard. The analyte and IS were extracted with solid-phase extraction and separated by a rapid isocratic elution with 1% formic acid/methanol (v:v, 40:60) on an C(18) column (150 mm × 2.1 mm I.D.). The detection was performed by mass spectrometry in the multi-reaction-monitoring mode. The precursor to product ion transitions of m/z 471.3→161.2 and m/z 397.2→313.1 were used to measure the analyte and the IS. The assay was linear over the concentration range of 0.0783-10 ng/mL for limonin in human urine. The lower limit of quantification was 0.0783 ng/mL and the extraction recovery was larger than 76.7% for limonin. The inter- and intra-day precision of the method at three concentrations was less than 7.4%. The method was successfully applied to pharmacokinetic study of limonin in humans.
authors.affiliation: State Key Laboratory of Natural Medicines (China Pharmaceutical University), Nanjing 210009, China.
authors.forename: Shijia
authors.initials: S
authors.lastname: Liu
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: Ling
authors.initials: L
authors.lastname: Zhou
authors.forename: Boyang
authors.initials: B
authors.lastname: Yu
authors.forename: Changyin
authors.initials: C
authors.lastname: Li
authors.forename: Zixiu
authors.initials: Z
authors.lastname: Liu
authors.forename: Wenzheng
authors.initials: W
authors.lastname: Ju
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D004355:Drug Stability; D005260:Female; D006801:Humans; D036701:Limonins / Q000737:chemistry / Q000302:isolation & purification / Q000493:pharmacokinetics / Q000652:urine*; D016014:Linear Models; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D052616:Solid Phase Extraction / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry / Q000379:methods*; D055815:Young Adult
chemical_list: D036701:Limonins; C001546:limonin