Spectrophotometric Determination of Strychnine in Brucine Sulfate (or the Alkaloid)

Abstract A method is described for the quantitative determination of strychnine in brucine or brucine sulfate. In the method, brucine is nitrated and strychnine is extracted with chloroform (as in National Formulary IX). The chloroform is then evaporated and strychnine is determined spectrophotometrically by dissolving the residue in O.1 N H2SO4 and measuring absorbances at 254 and 275.5 mμ. The difference between these absorbances, compared with similar differences at these wavelengths for standard strychnine solutions, is a measure of the strychnine content. Eleven tests over a range from 1 to 12.5% strychnine in brucine gave results with a standard deviation of less than 0.03%