a. Lab experiment title and data: Isolation of the active ingredient in an Analgesic Drug February 12th, 2013 b. Abstract ( purpose): Identify analgesic drugs after isolating the active ingredients from tablets. c. Physical data table Drug| Melting point| Brand names| Acetylsalicylic acid| 135-136 °C| Aspirin, ASA, acetyl salicylic acid, generic aspirin, empirin. | Acetaminophen| 169-170. 5 °C| Tylenol, Datril, Panadol, nonaspirin pain reliever. |
Ibuprofen| 75-77 °C| Advil, Brufen, Motrin, Nuprin. | d. Procedure: Extraction of active ingredient: Two tablets Ibuprofen (0.400g) was crushed into powder between 2 pieces of weighing paper by a pestle. Ibuprofen contained a red coat, was odorless, round and long as a regular tablet. After first crush, forceps were used to remove red fragments.
The powder after crushing had white color and also odorless. All white powder was added to a 3mL conical vial. Next, 2mL of Methanol was added to the vial by a calibrated Pasteur pipet. Then the vial was capped and mixed by shaking. During the experiment, the cap was loosened once to release any pressure that may have built up in the vial.
A cloudy suspension appeared at bottom of the vial after shaking about 4-5 minutes. Until the precipitate had settled completely, the liquid phase was transferred to a centrifuge tube and this extraction was repeated with a second 2mL of Methanol. The liquid was clearer after second shaking. After that, the mixture was centrifuged about 2 minutes and 30 seconds (setting high speed at 2). After centrifuge, clear liquid appeared above the white-pink solid. Next, the liquid was transferred to a regular test tube. Column Chromatography:
A Pasteur pipet was used to prepare an alumina column. The small ball cotton was pushed down to the bottom of pipet by a wooden-stick. Alumina (0. 5g) was added to the pipet (about approximately 2cm high of alumina in the pipet). A small beaker was placed under the column. To the column, 2mL of methanol was added and the liquid was allowed to drain until the Methanol reached the top of the alumina. The solution containing the drug from test tube was then transferred to the column. After that, an additional 1ml of methanol was added to the column.
The filtrate was clear and odorless. The filtrate was placed into a small beaker, covered with a watch glass; the solvent was evaporated overnight for a couple days. Evaporation of solvent: After completely dry, the product had appeared as a white crystal form at the bottom of the beaker and had no smell. Methanol was heated to a boiling point at 65 °C. Next, methanol was poured into the crystal and stirred. The solution was left to cool to room temperature on a pack of towels on top of the table. When cooled, the solution was placed in an ice bath for 10-15 minutes.
Vacuum Filtration: A Hirsch funnel was first set up. The filter paper was moistened by a few drops of methanol. The material was transferred to the Hirsch funnel by a micro spatula. The crystal was allowed to dry about 5-7minutes, and then the compound looked slightly sticky. The dried crystals were scraped from the filter paper onto the watch glass. Next, the watch glass with the crystal was weighed to calculate the weight of analgesic drug. The crystals or products were crushed again into powder to determine their melting point. e. Data presentation Items| Measurements|.
Mass of beaker + crude| 20. 401g| Mass of watch glass| 25. 431g| Mass of watch glass + pure| 25. 600g| M. P of final product| 77-80 °C| Literature M. P of Ibuprofen| 75-77 °C| Mass of final product= (mass of watch glass + pure) – (mass of watch glass) =25. 600g – 25. 431g = 0. 169g Weight of substance isolated Weight percentage recovery= x100 % Weight of original material 0. 169g = x100 % 0. 400g =42. 3% f. Data Analysis: *The final product was a white crystal. The mass of recovered product was 0. 169g and the percentage recovery of this product was 42.
3% which is about 57. 7% lower than 100%. *The melting point of final product was recorded at 77-80 °C which is about 2-3 degrees higher than the range (75-77 °C) in the laboratory textbook. g. Conclusion In this experiment, the mass of recovered product was 0. 169g and the percentage recovery of this product was 42. 3% which is about 57. 7% lower than 100%. This result was relatively low, but several factors during the experiment may have affected the recovery loss. First, when Ibuprofen was crushed, the white powder leaked out a little.
The product in this experiment had to be transferred into another container like transferring the product from the conical vial to the centrifuge tube, or from centrifuge tube to a small beaker. The drug was left behind and it could have also dropped into the beaker when during filtration with the cotton ball. The more steps of transferring the product meant the more amount of the product lost. The melting point of final product was recorded at 77-80 °C which is about 2-3 degrees higher than the range (75-77 °C).
Therefore, the product was contaminated. The reason for that is the product may still have contained water. Water could have come from the air or surrounding area during the drying process. Post- Lab Questions: 1,4,5,6. 1. The percentage recovery was less than 100% because the drug leaked during the experiment especially when Methanol was placed into the Pasteur pipet. The drug leaked when it was crushed or transferred, and it was left behind after centrifuge. Not enough Methanols may have been added. 4.
The alumina column was used for purifying an analgesic drug. 5. Percentage recovery Weight of substance isolated Weight percentage recovery= x100% Weight of original material 0. 185g = x100% = 52. 9 % 0. 350g 6. The melting point was low and the melting range of the product was so wide because the product was still contaminated (it contained some extra product that isn’t Acetaminophen which blocked its melting point to reach the original melting point). It also contained water that could have lead to incorrect melting points of the final product.