Advantages And Disadvantages Of Excicessing

Aspirin, Caffeine and Salicylamide were extracted from an over-the-counter pain reliever (BC Powder). These components were separated by manipulating their solubilities by adjusting the acidity and basicity of the solution. By doing this, the three components were forced into conjugate acid (or base) forms, causing selective solubility in either an aqueous or organic solvent. These layers were then separated by use of a separation funnel. Once separated, the components extracted were characterized by measuring the melting point and performing a TLC analysis. Also, the recovered aspirin from the first part of the experiment was recrystallized and compared to that of the

Discussion The third experiment of the semester involves identifying an unknown component of Panacetin, a common pain relief medication, separated and precipitated in the previous experiment. Although Panacetin’s label reports this third ingredient as Tylenol, there is controversy over the true classification of the third substance. This Panacetin label also reports that the unknown constituent makes up 50% of the composition of Panacetin, compared to aspirin’s 40% composition and sucrose’s 10% composition, meaning that it is currently unknown what half of the drug people ingest is identified as. Research results have failed to repeatedly show that the third component of Panacetin is Tylenol, which leads to the hypothesis

Me and my lab partner, obtained a mixture of a un known proportion from the instructor and then flow the guide line in our lab manual to separate the mixture by applying the separation method motioned in our lab manual pages 33-40 . In this experiment, the separation methods were decantation,

When the crude product is transferred to a separatory funnel, it is washed with 10 ml of water. When the solution forms two layers, the bottom aqueous layer is disposed of.

These layers can be separated through the use of a seperatory funnel which drains the bottom layer into a separate container. This method uses the understanding of partition ratios of solutes to different paired solvents to produce an equilibrium leaning towards one solvent over another, thereby extracting a compound from one liquid to the other (Padias 128-37). For example, consider a mixture containing two solutes, solute A and solute B, and two immiscible solvents, solvent A and solvent B. If solute A dissolves well into solvent A, but not very well into solvent B, and solute B dissolves well into solvent B but not very well into solvent A, there would be a higher ratio of solute A in solvent A than in solvent B, and a higher ratio of solute B into solvent B than in solvent A. One can then see that, through the use of different solvents, two dissolved solutes can be separated from a mixture. This ratio of a solute concentration to different solvents is defined by K, the distribution constant. Successive filtrations yield’s a higher percentage of products.

This experiment was done in order to understand both fractional distillations and gas chromatography. In addition, this experiment was done to separate and identify two liquids that made up an unknown mixture. Gas chromatography was used to figure out the ratio of these two liquids.

The crude product was washed by taking the reaction product in the separatory funnel and adding 23 mL of deionized H2O. The mixture was shaken and allowed to settle until layers were observable. The top layer was the desired product and approximately 25 mL of aqueous layer was extracted from the separatory funnel. Next, 25 mL of 5% NaHCO3 was added to the separatory funnel in order to neutralize the acid. This mixture was swirled, plugged with the stopper and inverted. Built-up gas was released by turning the stopcock to its opened and closed positions, releasing CO2 by-product. This was done four times in one minute intervals. The solution was allowed to settle until layers were observable. The bottom layer that contained salt, base and water was extracted from the separatory funnel. The crude product was washed again as mentioned previously.

Manufacturing theophylline formulations come with challenges for both the anhydrous and hydrate. For the anhydrous form, a study showed that the wet granulation of theophylline anhydrous in conjunction with microcrystalline cellulose, led to the formation of the monohydrate form of the drug. This is significant because the monohydrate has slower dissolution than the anhydrous form of theophylline. Thus the method of manufacture is highly important as the study showed directly compressed pellets had better dissolution profiles. Also it shows the importance of the choice of excipients as pellets manufactured via wet granulation in the absence of microcrystalline cellulose showed similar release to that of directly anhydrous theophylline.

7. Plan: Each student in a group of three will work to purify the product of the reaction with cis-stilbene, trans-stilbene, or styrene. The crude products will be purified through recrystallization. This purification process will be performed several times. When the recrystallization is complete, a vacuum filtration will be executed to filter out the crystals. An NMR spectrum will be taken of the recrystallized product.

Recrystallization purifies a crude product by separating the product from impurities based on solubility. The product being purified should easily dissolve in the chosen solvent at high temperatures, but not at room temperature. Impurities should dissolve in the solvent at room temperature but not at high temperatures.

• Due to its high separation efficiency, the quality of substance obtained by preparative mode or technique (prep HPLC) is of high purity.

As the acid was being added, the mixture was being stirred over a stir plate. Once completed, the reaction mixture was poured from the round bottom flask into a 500 mL separatory funnel and its top (organic) layer was extracted into another beaker. The bottom (aqueous) layer was placed back into the funnel and extracted twice with 50.0 mL of ethyl ether each. The newly extracted layers were combined and dried over magnesium sulfate (MgSO4). The dried solution was the decanted into a beaker to remove the MgSO4 salts and the product solution was collected via Buchner vacuum filtration. The resulting product was transferred into an Erlenmeyer flask with an inverted beaker on top and stored in a drawer.

However, if we were to proceed with Distillation first, we could elimate all contiante in the mix, as seen in the demonstration in Experiment 1. These would make the process of decantation, filtration, solvent extraction, adsorption redundant. In Nature: 439 (Martyn J, et al. 2006) it is said that;

A good yield of isopentyl acetate was obtained during this experiment. Loss of the product was likely through transferring liquid from separatory funnel to the Erlenmeyer flask and residual material left in the distillation flask. Using an organic solvent like benzene or cyclohexane as a transfer agent would improve the yield, since their boiling points were around 80 oC and could be easily separated from the final product through simple distillation. However this

Once cooled, the mixture was then transferred to a separatory funnel using the funnel while avoiding adding the boiling chip. 10 ml of water was then added to the mixture. The mixture was gently shaken and the phases were allowed to separate. The funnel was then unstopped and the lower aqueous phase was drained into a beaker. 5 ml of 5% aqueous NaHCO3 was added and then shaken gently. A great deal of caution was taken into consideration because of the production of carbon dioxide gas which caused pressure to develop inside the funnel. The pressure needed to be released so the funnel was vented frequently. The phases were allowed to separate and the lower aqueous phases was drained into the beaker. After draining, 5 ml of saturated NaCl was added to the funnel and then shaken gently. Once again, the phases were allowed to separate and the lower aqueous phase was drained into a beaker. An ester product was produced and was transferred into a 25 ml Erlenmeyer flask. This organic product was then dried over anhydrous Na2SO4 to trap small amounts of water in its crystal lattices thus removing it from the product. Finally the ester was decanted, so that the drying agent was excluded from the final product.