ABSTRACT
Objective An analytical approach has been developed for determination of sildenafil blood with high performance liquid chromatography.Methods Sildenafil was extracted by solid phase extraction cartridges from blood and was separated by resered-phase gradient chromatography with DAD detection at 230nm.The analytical column was Nova-pak C18(150×3.9mm),5.0μm and the guard column was Phenomenex C18(ODS,4.0×3.0mm,Octadecyl).The mobile phase Was gradient mixture of acetonitrile(A) and 0.25% acetonitrile aqueous solution including 0.06% trifluoroacetic acid and 0.06% triethylamine (B).Results Linearity Was checked over the concentration range 1.5～80.0μg/mL.Limits of detection was 5.0ng.Average recovery was 82.45%.Conclusion This method issimple.exact and rapid.
ABSTRACT
AIM: The study was undertaken to explore the dynamic changes of the concentration of nitric oxide(NO) in ischemic myocardium and its mechanism.METHODS: In vivo myocardial ischemia of mice and in vitro perfused isolated heart of rat were used in the experiment. The effects of severity and time of ischemia on NO production, NOS activity and mRNA were examined, respectively. RESULTS: There was a considerable difference (P
ABSTRACT
Objective An analytical approach has been studied lor high performance liquid chro-matographic determination of Diphacinone and its metabolites extracted from urine. Method Diphacinone and its metabolites extracted from rabbit urine by solid phase extraction (SPE) cartridges (CN and SAX) were analyzed with coumarin as the internal standard. Diphacinone and its metabolites were separated by reversed-phase gradient chromatography with DAD detector at 311nm. The analytical column was Hypersil BDS C18 (150mm?4.6nmi. d. ) and the guard column was Phenomenex ODS (4mm?3.0mmi. d.). The mobile phase was a gradient mixture of aqueous solution (A) and methanol solution (B), both containing 0.5% ion pair A. Results Eleven diphacinone metabolites were detected in poisoned rabbit urine by this method. Conclusion This method is simple, exact and rapid.