1 Isolation of Aspirin
Introduction
We will use our first experiment of the semester to dust off your practical and theoretical laboratory skillset. In your Organic Chemistry I laboratory, you learned a variety of isolation and separation techniques, including recrystallization, liquid–liquid extraction, chromatography, and filtration (among others). You will now put your understanding of these techniques to the test.
Experiment Overview
You will be given 2 packs of Bayer® Rapid Relief Powder Packs. Your job is to isolate the aspirin. That’s it!
You should arrive with a tentative plan to achieve this task. You can (and should) discuss your strategies with your labmates and TA.
Safety and Waste
Do not consume the powder packs. Though they are commercially available, they are contaminated by virtue of being in the lab.
As always, appropriate lab attire and PPE are expected. Goggles must be worn any time chemicals or glassware are out and in use anywhere in the lab.
You should include a safety note for any acids, bases, or other potentially hazardous compounds that you plan to use.
Experimental Procotol
You will develop your own protocol. Once you have a sample in hand, you should confirm the structure using infrared spectroscopy (IR).
You will compare your IR data against the IR spectra of:
- Commercial Bayer aspirin pills – You should consider how to obtain an IR spectrum of a pill.
- Synthesized aspirin (made by CHEM 238!) – For your reference, CHEM 238 runs the following reaction:
Some Guiding Questions:
- What are the active and inactive ingredients? What are the key compounds you should consider during this exercise?
- Consider the key compounds: Are there any distinguishing chemical features that might be useful for separation? For characterization?
- Your fume hood/drawers contain everything you need to achieve this task. What does that tell you about the techniques you might consider?
- You should plan to use a rotary evaporator. Your TA will show you how once you reach that point.
(more commonly: rotavap) a device used for the gentle and efficient removal of solvent from a sample by evaporation