Spectrophotometric determination of atropine sulphate

Atropine reacts with sodium nitrite and 1-naphthylamine when heated from 95 -100°C giving an orange color with a maximum absorbance at 464 nm. This reaction is greatly affected by the pH of the solution and the time of heating. The assay obeys Beer's law in concentrations ranging from 10-800 micro g/ml and the visual limit of detection [LOD] is 0.5 micro g/ml. It has been postulated that obidoxime chloride may interfere with this reaction if co exists with atropine sulphate in the same solution or preparation, as this mixture is widely used for the treatment of organo-phosphorus pesticides poisoning