Identification et dosage de l'acide 5-hydroxyindolacétique

Pharmaceuticals and Related Drugs

“…of alkaloid by subliming the pure material, its salts, or crude drugs containing them and viewing the sublimate with a microscope. Caffeine in a mixture containing theobromine and theophylline can be determined photometrically according to Wachsniuth and van Koeckhoven (532). A photonephelometric method for the determination of caffeine, based on the use of tungstophosphoric acid, has also been presented (49).…”