title: [Determination of cyclovirobuxine D by RP-HPLC with precolumn fluorescence derivatization].
abstract: OBJECTIVE
  To establish a RP-HPLC method for determination of cyclovirobuxine D.
  
  
  METHODS
  Cyclovirobuxine D reacted with a derivative reagent 1-naphthyl isocyanate in chloroform to form fluorescence derivatives, stopped the reaction by adding the mobile phase and then directly injected the solution into the chromatograph to seperate it by RP-HPLC. The analysis was carried out on C18 column, the mobile phase is methanol-water (85:15), the excitation wavelength was set at 305 nm, emission at wavelength 385 nm, and the flow rate was 1 mL.min-1. The effect of several factors including the reaction medium, temperature, time and amount of 1-naphthyl isocyanate on the yield of the derivatization was also investigated systematically.
  
  
  RESULTS
  A simple and rapid RP-HPLC method for the simultaneous isolation and analysis of cyclovirobuxine D and its related substances was developed, and the absence of interference between the derivative peak responses of cyclovirobuxine D and its related substances were verified by UV diode array detecter and MS. The linearity was obtained from 0.75 microgram.mL-1 to 2.5 micrograms.mL-1 of cyclovirobuxine D derivatives with a correlation coefficient of 0.9991. The detection limit of cyclovirobuxine D derivative was 1 ng.mL-1, the repeatability of derivatization was good with relative standard derivation no more than 1.2% and derivative was stable within 48 h. The method described conforms to the validation of China Pharmacopiea compendial methods used for pharmaceutical products in general.
  
  
  CONCLUSIONS
  The established method is proved to be reliable quantitative method for the quality control of cyclovirobuxine D.
authors.affiliation: Department of Pharmaceutical Analysis, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Xin-jun
authors.initials: XJ
authors.lastname: Xu
authors.forename: Zheng-xing
authors.initials: ZX
authors.lastname: Zhang
authors.forename: Long-sheng
authors.initials: LS
authors.lastname: Sheng
authors.forename: Gao-li
authors.initials: GL
authors.lastname: Liu
authors.forename: Deng-kui
authors.initials: DK
authors.lastname: An
mesh_terms: D031235:Buxus / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004365:Drugs, Chinese Herbal / Q000032:analysis* / Q000302:isolation & purification; D010946:Plants, Medicinal / Q000737:chemistry; D011786:Quality Control
chemical_list: D004365:Drugs, Chinese Herbal; C032939:cyclovirobuxine D