1. EXTRACTION of ANALGESICS
Experiment 6:
EXTRACTION of ANALGESICS

2. Objectives To learn the technique of acid-base extraction.
To separate aspirin from acetaminophen using the extraction technique.
To learn the techniques of drying organic solvents and vacuum filtration.
To analyze the purity of the aspirin and acetaminophen samples using HPLC analysis.

3. Before coming to lab…
Watch the following videos to help you understand the techniques that will be used.
Extraction
Vacuum Filtration
Drying Organic Solvents

4. ACTIVE INGREDIENTS— GOODY’S POWDERS
500 mg/powder mg/powder

5. ACID–BASE EXTRACTION— CHEMICAL EQUATIONS

6. ACID–BASE EXTRACTION FLOW CHART

7. SEPARATORY FUNNEL TECHNIQUE
Be sure the stopper is tightly sealed before inverting!
Always keep one finger on the stopper!
Be sure the stopcock is in the horizontal position (closed) before adding any liquid!

8. SUCTION FILTRATION TECHNIQUE
Always clamp the suction flask to a ring stand!
Run the red vacuum hose to the yellow vacuum line to pull suction!
To vacuum line…

9. DRYING ORGANIC SOLVENTS
Add a small amount of MgSO4 to the organic solution and swirl.
If the MgSO4 continues to clump and sink to the bottom, continue to add.
If the MgSO4 settles out of solution slowly (like a snow globe), the solution is dry.

10. OVERVIEW Perform acid/base extraction using separatory funnel.
Isolate ASPIRIN and ACETAMINOPHEN in separate flasks.
ACETAMINOPHEN (O)
ASPIRIN SALT
(A) A O

11. OVERVIEW ACETAMINOPHEN… Dry organic layer with MgSO4.
Suction filter to remove MgSO4 from liquid.
Evaporate liquid on hotplate.
Reweigh to obtain final weight & calculate % recovery.
Dissolve solid in REAGENT acetone.
Submit HPLC sample.
Transfer to large sample vial and submit to instructor until next lab period.

12. OVERVIEW ASPIRIN… Add acid to recover solid aspirin.
Suction filter to recover solid aspirin.
Submit HPLC sample.
Secure aspirin in large filter paper and submit to instructor until next lab period.
NEXT LAB PERIOD…
Obtain final weight of aspirin.
Calculate % recovery.
Prepare sample for melting point analysis.

13. THEORETICAL RECOVERY
For this experiment, we dissolved 2 Goody’s powders in 25 mL of ethyl acetate.
In each Goody’s powder, there is g of aspirin and g of acetaminophen.
Theoretical Recovery:
0.500 g per powder X 2 powders = ? g of Aspirin
0.325 g per powder X 2 powders = ? g of Acetaminophen

14. PERCENT RECOVERY
After the product has been dried sufficiently, the ACTUAL YIELD can be determined.
In theory, you should be able to recover 100% of each compound, however this is not always the case.
In order to determine the success of your recovery, the percent yield is calculated as follows:
Percent recovery : actual recovery (g) X 100
theoretical recovery (g)

15. Table 6.1 Aspirin Acetaminophen
Theoretical recovery after extraction (g)
calculated
Actual recovery after extraction (g)
Obtain weight
next lab!
Obtain weight this lab!
% Recovery after extraction

16. HPLC retention times (min) and area %
Table 6.2
Compound
HPLC retention times (min) and area %
Standards
Aspirin
Sample
Acetaminophen Rt
(min)
area %
Samples containing a single compound are considered PURE samples, while those containing both compounds are considered MIXED (IMPURE) samples.
Be sure to attach both sample chromatograms to final lab report!

17. SAFETY CONCERNS
Acetone and ethyl acetate are extremely flammable! Wear safety goggles at all times and use extreme caution when heating!
Hydrochloric acid is corrosive!

18. WASTE MANAGEMENT
The drying agent (MgSO4) and filter paper should be placed in the container labeled “MgSO4 Waste” provided in the hood.
Place all liquid waste in the container labeled “ACIDIC AQUEOUS WASTE”.

19. LABORATORY NOTEBOOK (Pre-lab)
OBJECTIVE (Must clearly state…)
What is the goal of the experiment?
How will you accomplish this goal?
How will you determine if it worked?
TABLE OF PHYSICAL DATA (Complete the following table using MSDS sheets from a site on WWW Links ONLY. Wikipedia is unacceptable)
REFERENCE TO PROCEDURE (Must include…)
full title
Edition
authors
page numbers where actual procedure can be found
Compound
MW (g/mol)
bp (Co)
mp (Co)
d (g/mL)
HAZARDS
Acetone
XXX
Ethyl acetate
Hydrochloric acid
Sodium bicarbonate
Aspirin
Acetaminophen

20. LABORATORY NOTEBOOK (In-lab)
DATA/CALCULATIONS
EXTRACTION:
Theoretical recovery CALCULATION for aspirin (not just the value!)
Theoretical recovery CALCULATION for acetaminophen (not just the value!)
DRYING AND ACETAMINOPHEN RECOVERY:
initial weight of 150 mL beaker
weight of 150 mL beaker+ acetaminophen
ASPIRIN RECOVERY:
Weight of small filter paper
Weight of large filter paper
HPLC ANALYIS:
HPLC vial slot # for aspirin sample
HPLC vial slot # for acetaminophen sample
EXPERIMENTAL PROCEDURE
In paragraph form, briefly describe the procedure that you actually followed during the lab.
Paragraph must be written in PAST TENSE, PASSIVE VOICE.
Include any volumes or weights of chemicals used during the experiment.
Include any mistakes, accidents, or observations if necessary.