[Determination of cyclovirobuxine D by RP-HPLC with precolumn fluorescence derivatization].

AIM: 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. CONCLUSION: The established method is proved to be reliable quantitative method for the quality control of cyclovirobuxine D.