TLC Analysis of Analgesic Drugs
Introduction
The purpose of this experiment was to use thin-layer chromatography (TLC) to determine the composition of various over-the-counter analgesics (acetaminophen, aspirin, caffeine and salicylamide). The methods necessary was thin-layer chromatography
Experiment Scheme
Prepared at least 12 capillary micropipets to spot the plates. Then obtain two (silica) TLC plates and handle them carefully or the adsorbent may flake off. Handled them only by the edges. Used a lead pencil lightly draw a line across the plates about 1 cm from the bottom. Used a ruler, move it index about 0.6 cm in from the edge of the plate and lightly mark off five 1 cm intervals on the line. These points at which the samples will be
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They all have a stationary phase and a mobile phase. The mobile phase flows through the stationary phase and carries the components of the mixture with it. Different components travel at different rates (Harry W, 1989). For the reference plate, it can determine the Rf values of each analgesic (acetaminophen, aspirin, caffeine, salicylamide and index the reference mixture). There are two visualization methods used in the experiment. The two visualization methods are use short-wavelength ultraviolet lamp and use iodine vapor. For the first method, there are some spots appeared dark on the plate and some appeared blue. From the difference appearance, we can determine the composition of the analgesics. For the first method, there are some spots appeared light yellow or dark yellow. The difference colors can let us distinguish them. And we also measured the distance about the spot traveled to the front of solvent. And we calculated the Rf values of each spot. All of our observation was shown in the Table 2 and Table 3. So, after comparison, we can know Anacin might contain acetaminophen or salicylamide. Excedrin might contain acetaminophen or salicylamide. Buffrin might contain