The Chemistry of Lindo and Fages Colour Tests

Abstract

Lindo test for strychnine identification is based on the reaction of the alkaloid with potassium chlorate in the presence of sulphuric acid. Fages identified chlorates and bromates using strychnine in nitric acid. In fact, it is the same reaction but with different strong acid, and the product to be identified being interchanged. The reaction series occurring in these tests has not being described. We provide the electron flow from the alkaloid to the complex oxidation product resulting from the powerful oxidation properties of chloric acid.