Separating the Components of Panacetin

Introduction:

To decide whether the composition of the provided "Panacetin" matches as stated on the label. To separate the components of the substance to later identify the unknown component in Panacetin. We were expected to separate and obtain the three different ingredients found in the drug "Panacetin": sucrose, aspirin, and an unknown component.

I separated sucrose from the mixture of Panacetin with dichloromethane using a centrifuge. I extracted the dichloromethane solution with two separate 4-mL portions of 5% NaHCO3 and transferred the organic and aqueous layers to separate 20-mL beakers. I collected aspirin by adding hydrochloric acid to the aqueous solution and then using vacuum filtration with a Hirsch funnel.

Substances:

Aspirin

Acetanilide

Acetaminophen

Phenacetin

Sucrose

Data, Calculations, and Results:

Starting mass of Panacetin 0.404 g

Sucrose

Weight of Centrifuge tube 17.118 g

Weight of Centrifuge tube with Sucrose 17.150 g

Mass of Sucrose 17.150g-17.118g= 0.032 g

Percent Recovery 0.032g/0.404g= 0.07920 x 100 = 7.920%

Aspirin

Weight of Filter Paper 0.172 g

Weight of Filter paper with Aspirin 0.240 g

Mass of Aspirin 0.240g- 0.172g = 0.068g

Percent Recovery 0.068g/0.404g = 0.168316 x 100 = 16.831%

Unknown Component

Weight of beaker without unknown 28.843g

Weight of beaker with unknown 28.997g

Mass of Unknown 28.997g - 28.843g = 0.154g

Percent Recovery 0.154g/0.404g = 0.38118 x 100 = 38.1188%

Discussion and Observations:

By taking advantage of the differences in physical and chemical properties of certain compounds we were able to separate "Panacetin" into its three constituent parts. Our first process was the separation of sucrose. Aspirin, acetanilide, and phenacetin are all soluble in dichloromethane, while sucrose is not. After mixing the Panacetin with the dichloromethane, the aspirin and unknown component were dissolved, leaving behind the insoluble solid of sucrose. In this experiment, we separated the sucrose from the rest of the solution by centrifugation. After about three minutes of centrifugation, there was clear separation between the liquid solution and the solid sucrose residue. We were then able to transfer the liquid solution into another centrifuge tube and allow any remaining dichloromethane to evaporate to obtain our sample of sucrose.

Our next process was to separate aspirin from the solution. When aspirin interacts with the base sodium bicarbonate, it converts into sodium acetylsalicylate. To do this we removed the aspirin using the extraction operation. Aspirin's sodium salt will migrate from the bottom dichloromethane layer where it is insoluble to the top aqueous layer, in which it is soluble. Performing the extraction two separate times, we took our combined aqueous layers of sodium acetylsalicylate with water that we separated from the dichloromethane layer and added HCl to transform it back into aspirin. Then by performing vacuum filtration and drying the substance, we were able to obtain our sample of aspirin.

Our final step was to isolate our unknown component from its organic layer. To do this we simply evaporated the solvent from the dichloromethane solution to obtain our unknown component. Since acetanilide and phenacetin are not converted into salts by sodium bicarbonate, we can be positive that at least one of these substances is our unknown since it stayed in our organic layer.

My results for percent recovery of