Isolation of Components

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Pure fractions are concentrated to isolate each component.

What should we do with these fractions?

Discuss (IN-LAB #5):

Explain the order of separation of Excedrin components on the column given what you know about functional groups, polarity, and acid-base chemistry (HINT: hydrogen-bonding and ion-dipole interactions should be included in your discussion).
Were the results as expected?

Once you've determined which fractions to keep/combine or discard:

Add fraction(s) to a pre-weighed RBF
Concentrate each component in vacuo
Measure the mass of isolated component + RBF
Calculate the mass of isolated component by difference

ASP_comb.mp4

ASP

Subtract 1 mg ASP at this step

ACE_comb.mp4

ACE

Subtract 1 mg ACE at this step

CAF_comb.mp4

CAF

Subtract 3 mg ACE and 5 mg CAF at this step

Discuss:

List reasons for product loss at this step (part of IN-LAB #4)
What can be done next time to prevent the major losses of ACE and CAF during the isolation of CAF?

For the remote lab (IN-LAB #3 and part of #4):

A. Calculate the mass recoveries for each component (ASP, ACE, and CAF)

- Subtract the total mass lost of each component during the remote lab from the theoretical masses that were calculated at the beginning of the experiment

B. Calculate the "actual" percent recoveries for each component

- (mass of component recovered / mass of Excedrin) *100

Note: Determining the mass recoveries is much simpler during the in-person labs! The mass recovery would be obtained directly from the balance (see steps 1-4 listed above) – no calculation required except for subtracting the mass of the RBF.

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