title: [UPLC-MS/MS method for the determination of icaritin in rat plasma].
abstract: OBJECTIVE
  To establish an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the quantification of icairitin (ICT), and investigate pharmacokinetics of ICT in rats following a single intravenous administration.
  
  
  METHODS
  ICT and an internal standard coumestrol (CMT) were extracted from rat plasma using acetonitrile and separated on a BEH C18 column (2.1 mm x 50 mm, 1.7 μm) using a gradient mobile phase of acetonitrile, water, ammonium formate and formic acid at a flow rate of 0.3 ml/min. At negative electrospray ionization mode, multiple reaction monitoring of the precursor-product ion transitions of m/z 367.1-->297.1 for ICT, 267.0 --> 211. 1 for CMT was used for the quantification. Plasma was collected after rats were intravenously administered with ICT at a single dose of 10 mg/kg.
  
  
  RESULTS
  The linear calibration curve was obtained in a concentration range of 0.5 - 20 ng/ml with a lower limit of quantification of 0. 5 ng/ml. The value of intra- and inter-day precision was less than 8.1% and accuracy fell in the ranges of 95.3% - 99.3%. The recovery ranged from 90.1% to 92.1% and the matrix effects from 97.5% to 101.2%. After intravenous administration of ICT to rats, t½ was(1.13 ± 0.32) h, V was(4.54 ± 0.27) L/kg, and CL was (2.91 ± 0.68) L/(h x kg).
  
  
  CONCLUSIONS
  The method was rapid, specific and accurate, suitable for preclinical pharmacokinetics of ICT.
authors.affiliation: National Institute for Nutrition and Food Safety, China Center for Disease Control and Prevention, Beijing 100050, China. zhangshq@hotmail.com
authors.forename: Shuangqing
authors.initials: S
authors.lastname: Zhang
authors.forename: Zhenwu
authors.initials: Z
authors.lastname: Huang
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002853:Chromatography, Liquid; D003375:Coumestrol / Q000097:blood; D004305:Dose-Response Relationship, Drug; D005419:Flavonoids / Q000008:administration & dosage / Q000097:blood* / Q000302:isolation & purification / Q000493:pharmacokinetics*; D051381:Rats; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D005419:Flavonoids; C499403:icaritin; D003375:Coumestrol