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Lab.6. Identification Of Caffeine Crystals. Pharmacognosy 3rd Class, 2nd Semester. Identification of Caffeine Crystals. Quantitative analysis By weight the crystals of the caffeine. Qualitative analysis. Chromatography TLC. Chemical test The muroxide test. Qualitative analysis
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Lab.6 Identification Of Caffeine Crystals Pharmacognosy 3rd Class, 2nd Semester
Identification of Caffeine Crystals Quantitative analysis By weight the crystals of the caffeine Qualitative analysis Chromatography TLC Chemical test The muroxide test
Qualitative analysis 1) Specific Test The Muroxide test Aim: - To identify the caffeine alkaloid (Purine alkaloid) from other alkaloids. Equipments and reagents:- • Porcelain dish • Water bath • Potassium chlorate • Concentrated HCL • Ammonia vapor Procedure:- • Take few crystals of caffeine in porcelain. • Add small amount of potassium chlorate (KCLO3). • Add 2drops of concentrated HCL. • Evaporate to dryness. • Expose to ammonia vapor. Result:- A purple color is produced and other Purine derivative.
2) TLC Aim: - Used to identify quantitatively the Purine alkaloids. Equipments and reagents:- • Glass jar with its cover • Silica gel plates • Standard reagent • Mobile phase (acetone; water; ammonia (90; 7; 30) • Spray reagent (I/KI) • Capillary tube Procedure:- • Prepare the mobile phase and put in the glass jar, cover the jar and leave it for 45 min. for saturation. • Apply the sample and the standard by the use of capillary tube on the silica gel plate. • Leave the plate in the jar until the solvent reaches 3/4 of the plate. Remove the plate, dry, and then spray with the spraying reagent. • Calculate RF Value.