Collaborative study of a spectrofluorometric assay for Rauwolfia serpentina tablets and powdered root, using a vanadium pentoxide-phosphoric acid determinative step.
Reserpine-rescinnamine group alkaloids are extracted from Rauwolfia serpentina preparations into dimethylsulfoxide (DMSO)-methanol and diluted with 0.5N H2SO4. The chloroform extract of this solution is passed through a 0.1N NaOH-Celite column and then through a silica gel column. The weakly basic alkaloids trapped on the latter column are eluted with chloroform-methanol; a portion of the eluate is treated with a vanadium pentoxide-phosphoric acid solution, and the reserpine-rescinnamine content is determined by measuring the intensity of the resulting fluorescence. The following means and standard deviations (11 collaborators) were obtained for the determination of reserpine-rescinnamine group alkaloids in 4 samples of Rauwolfia serpentina (NF reference powder, 100 and 50 mg commercial tablets, and 45 mg synthetic tablet formation): 0.173%, 0.0050; 0.128%, 0.0030; 0.150%, 0.0069; and 0.142%, 0.0032; respectively. The method has been adopted as official first action.
D007202:Indicators and Reagents; D008722:Methods; D010087:Oxides; D010756:Phosphoric Acids; D011208:Powders / Q000032:analysis; D046948:Secologanin Tryptamine Alkaloids / Q000032:analysis*; D013050:Spectrometry, Fluorescence; D013607:Tablets / Q000032:analysis; D014639:Vanadium
D007202:Indicators and Reagents; D010087:Oxides; D010756:Phosphoric Acids; D011208:Powders; D046948:Secologanin Tryptamine Alkaloids; D013607:Tablets; D014639:Vanadium