Spectrophotometric determination of ajmaline and brucine by Folin Ciocalteu's reagent

Abstract

A rapid and simple spectrophotometric procedure is described for the determination of ajmaline and brucine. The method is based on the development of blue coloured product due to reduction of tungstate and or molybdate in Folin Ciocalteu's reagent (FCR) by ajmaline and brucine in alkaline medium. The colour is stable for more than 48 h. The chromogenic reaction has λ max at 540 nm with molar absorptivity 1.64 × 104 and 2.37 × 103 l mol-1 cm-1 in the Beer's law range 1-8 μg ml-1 and 10-100 μg ml-1 for ajmaline and brucine, respectively.