Lab 1: Isolating Caffeine PDF

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Lab report for the Isolating Caffeine lab with Steven Holmgren ...

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Isolating Caffeine from Caffeine Pills CHMY211-010 Natalie Brehaut 9/5/2019

Introduction In this lab, we broke down the contents of the caffeine pills, No-Doz, in order to isolate the pure caffeine substance of the pill, no other contents. This was done using a series of heating and cooling solutions as well as using a vacuum pump to filter out varying contents. The usage of the vacuum filtration was critical to this experiment as it could double filter out any impurities or contents other than the caffeine that we did not want. We identified a melting point range of the final sample using a Mel-Temp1. The purpose of this lab is to be looking at how we can isolate one part of a pill in its pure form. We would ideally be looking to recover 100% of the contents of the substance from breaking it down. This kind of lab is extremely important to the science community because it is a building block towards more advanced workings. To be able to have a compound or substance and isolate one aspect of that substance can lead to further understanding about its makeup. An experiment in the Malaysian Journal of Chemistry used similar techniques seen in our lab experiments to make conclusions about caffeine in popular soft drinks, tea, and coffee. They could then come to further conclusions about the classification of caffeine presented based upon its melting point2. This kind of isolation is important for further information can be determined about the kind of caffeine's effect on the human body. Generally caffeine is most often seen as an agent to increase alertness and remove a tired feeling. The research done on caffeine seen in this lab can be important to know at what point is too much, too much. From looking at the effects of pure caffeine on the body in varying amounts, it can be concluded that too much caffeine on the system can lead to cardiovascular problems, and some symptoms resembling those of mental illnesses3. With this being understood

and more research regarding the drug, there have been developments in what is considered a safe amount for an individual to consume without cause harsh effects either physically or mentally. Likewise in finding the consequences of caffeine, isolating the substance has allowed to find benefits in it as well. One popular topic regarding this is the use of caffeine in sports. A particular study looks at the usage of caffeine in sports and compares the results to that without caffeine. Due to the more lively nature caffeine provides on the body, when taking it there was an increased period of time before exhaustion, increased winning percentage, and an increased post recovery time. By isolating the particular substance entering the body, it is to be concluded that there are benefits to ingesting the substance prior to sport4.

Methods This lab began by weighing out one tablet of caffeine. Using a weigh paper and a thick glass vial, the caffeine pill was crushed into a fine powder. This powder was added to a 25 mL erlenmeyer flask along with 4 mL of 95% ethanol. The solution was heated in a boiling water bath, placing the flask in the bath and a test tube with 3 mL of ethanol. A vacuum filtration system was set up using a 25 mL filtration flask and a filter funnel. A small filter paper was added to the funnel with a bit of the warm ethanol poured over. The hot caffeine solution was poured through the filtration system with the vacuum running. The last bit of the warm ethanol was used to rinse the flask to rinse any remaining caffeine solution. What was filtered through was poured into a clean erlenmeyer flask and placed back in the hot water bath with a gentle stream of nitrogen blowing over the top. It is noted that when pouring the solution back into the flask, a significant amount was spilled and lost. Once about 2 mL of solution, it was removed from heat until room temperature. Once it appeared that crystallization began occurring, the flask was placed in an ice bath. Once cooled, we poured the remaining caffeine powder onto a weight paper. It was at this time that the yield of caffeine was lost. As a maintenance worker came in the room to work on the nitrogen supply, our nitrogen tube connected to this supply went off unknowingly and blew our caffeine yield away. Observing another groups work, we saw what was supposed to occur at this time. The remaining powder was placed in the filtration system with the vacuum and washed with a few drops of 50% ethanol. What was left was then dried to a constant mass and weighed. Using a Mel-Temp Machine and observing another group, a melting point range was gathered. The group took two samples of this measurement.

Results Original Weight of Caffeine Pill: 0.4392 grams Lost all isolated substance Final weight: N/A Mass Recovery: 0 g/ 200 g *100% = 0% mass recovery

Observation of Another Groups Melting Point Sample 1 First sign of melting: 206 ℃ Completely melted: 219 ℃ Sample 2 First sign of melting: 204 ℃ Completely melted: 230 ℃

Average Melting Range: 205-224 ℃

Discussion Due to circumstances of our lab and losing the final product, it is hard to come to final conclusions about what had occurred in our own experiment. From listening to other groups, it was concluded there were a number of impurities found in their samples or they were unable to get their samples to dry in the end leading to a final yield of over 100%. With samples that ended in a yield in less than 100%, it can be assumed that material may have been lost when crushing the tablet, or transferring it between flasks. Though ethanol was used to rinse the flask to keep as much of the caffeine as possible, it could have been that some still remained in the flasks after the rinse. In our case, some of the caffeine solution spilled when pouring between flasks which would have led to a lower recovery of caffeine if the experiment would have been completed to its full potential. Using a standard report of the melting point of caffeine, the melting point should be around 235 °C. Looking at the results gathered from another group with a range of 205-224 °C, it can be concluded that the sample gathered was fairly pure/isolated giving a nearly accurate reading.

Conclusions The purpose of this lab was to be able to isolate a pure substance, caffeine, coming from the form of a pill. With the right intentions of completing this lab, we were unsuccessful. We had isolated a small portion of the substance nearing the end of the lab but were unable to gather final measurements on what we had left or a melting point of that substance. Our initial hypothesis was that we would have a percent yield less than 100% and considering that all substance was lost due to circumstances it could be said that the hypothesis was correct. Though in observations of other groups, we saw results that were close to a 100% yield, some slightly over some less and a melting point that was near the true melting point of caffeine. For that reason it can be concluded that the isolation of caffeine from the form of a pill was successful from the methods that we used in this lab.

Citations 1. Isolating Caffeine from Caffeine Pills- Steven Holmgren 2. Mumin, A.; Akhter, K.; Abedin, Z.; Hossain, Z. Tea and Instant Tea in Solid Form. Determination of Caffeine Content. Method Using High-Performance Liquid Chromatography. Determination and Characterization of Caffeine in Tea, Coffee and Soft Drinks by Solid Phase Extraction and High Performance Liquid Chromatography 2006, 8 (1). 3. McKim, E. M.; WA, M. K. Caffeine: how much is too much? https://europepmc.org/abstract/med/8299103 (accessed Sep 10, 2019). 4. Sinclair, C.; Geiger, J. Caffeine Used in Sport: Should it be Allowed, Restricted, or Banned. https://www.researchgate.net/profile/Jonathan_Geiger/publication/12494990_Caffeine_us e_in_sports_A_pharmacological_review/links/57ed132608ae93b7fa9711ed/Caffeine-usein-sports-A-pharmacological-review.pdf (accessed Sep 9, 2019)....