EXTRACTION of ANALGESICS Experiment 6: EXTRACTION of ANALGESICS

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.

Before coming to lab… Watch the following videos to help you understand the techniques that will be used. Extraction http://www.wonderhowto.com/how-to/video/how-to-do-a-liquid-liquid-extraction-in-the-chemistry-lab-259811/view/ Vacuum Filtration http://video.google.com/videoplay?docid=-4541453194468704643#docid=1104445520143750871 Drying Organic Solvents http://www.wonderhowto.com/how-to/video/how-to-dry-an-organic-solution-in-the-chemistry-lab-259802/view/

ACTIVE INGREDIENTS— GOODY’S POWDERS 500 mg/powder 325 mg/powder

ACID–BASE EXTRACTION— CHEMICAL EQUATIONS

ACID–BASE EXTRACTION FLOW CHART

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!

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…

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.

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

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.

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.

THEORETICAL RECOVERY For this experiment, we dissolved 2 Goody’s powders in 25 mL of ethyl acetate. In each Goody’s powder, there is 0.500 g of aspirin and 0.325 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

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)

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

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!

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!

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”.

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

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.