Spectrophotometric determination of certain sympathomimetic amines

Abstract

The chromogenic agents p-anisaldehyde and p-tolualdehyde were used for the determination of the sympathomimetic amines methyldopa and noradrenaline. A purple colour developed when an alkaline solution of methyldopa and noradrenaline was allowed to react with p-anisaldehyde or p-tolualdehyde at pH 4.7. Beer's law was obeyed over the ranges 0.17–1.35 mg of noradrenaline and 0.24–1.68 mg of methyldopa. Benzaldehyde was also used for the determination of sympathomimetric amines. The results are compared with those obtained with official methods.