title: [Determination of 7-ethyl-10-hydroxycamptothecin in microdialysates from rat brain with LC-MS/MS].
abstract: To establish a method for determination of 7-ethyl-10-hydroxycamptothecin (SN-38) in microdialysates from rat brain.
  
  
  
  The concentrations of SN-38 were measured by LC-MS/MS method with Agilent Eclipse Plus C18 (2.1 mm ×100 mm, 1.8 μm) reversed phase column using acetonitrile-0.1% methanoic acid as mobile phase with gradient elution at a flow rate of 0.3 ml/min and temperature at 35 degree. Multiple reaction monitoring using the precursor to product ion combinations of m/z 393.1→349.1 was performed to detect SN-38 in microdialysates from rat brain.
  
  
  
  Blank microdialysate had non-interference. The method was linear over the concentration range of 0.1015-1015 ng/ml (r=0.9995); and the lower limit of quantification (LOQ) was 0.1015 ng/ml. The recovery of assay for SN-38 ranged from 97.54%-100.60%. The intra- and inter-day precision and stability were both well. The concentrations of SN-38 in brain microdialysates presented pharmacokinetics process and achieved the peak after 220 min.
  
  
  
  The fully validated LC-MS/MS analytical method has high specificity and sensibility, which can be used effectively to analyze SN-38 in microdialysates from rat brain.
authors.affiliation: Zhejiang Chinese Medical University, Hangzhou, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Cao
authors.forename: Qiaoyuan
authors.initials: Q
authors.lastname: Cheng
authors.forename: Hongyang
authors.initials: H
authors.lastname: Lu
authors.forename: Hengyi
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D002166:Camptothecin / Q000031:analogs & derivatives* / Q000032:analysis; D002853:Chromatography, Liquid / Q000379:methods*; D000077146:Irinotecan; D008297:Male; D017551:Microdialysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000077146:Irinotecan; D002166:Camptothecin