Question

Write Murexide test and give its significance. (Pharmacognosy And Phytochemistry-ll)

Answer 1

The murexide test is an analytical technique to identify the presence of caffeine and other purine derivatives in a sample. These compounds do not respond to the common alkaloid detecting tests such as Dragendorff's reagent. In this test the alkaloids are mixed with a tiny amount of potassium chlorate and a drop of hydrochloric acid. The sample is then evaporated to dryness and the resulting residue is exposed to ammonia vapour. Purine alkaloids produce a pink color in this test.[1][2] Murexide (ammonium purpurate) with a purple color is also produced in this test.[3][contradictory]