Spectrophotometric determination of submicro quantities of Ajmaline

A spectrophotometric method for the determination of 5–100 μg samples of ajmaline is described. Ajmaline gives a red colour with concentrated nitric acid, which is measured at 510 mμ after a definite time interval. The limits of interference from serpentine and ajmalicine are given. The method can be applied directly for the estimation of ajmaline in pharmaceutical preparations.