Abstract: The objectives of this lab are relatively simple: using a separatory funnel to separate a pure substance from a mixture, determine the mass of a sample of caffeine using mass spectrometry, and as a way to separate compounds, use gas chromatography. Using gas chromatography and mass spectrometry you are more accurately able to determine the sample of caffeine.
Amount of Caffeine in 100mL sample of Coffee.
Introduction: Within this lab, our group was supposed to determine the amount of caffeine that was in a 100mL sample of plain black coffee. First, we created a mixture of black coffee, sodium carbonate, and ethyl acetate in an Erlenmeyer flask. We used a separatory funnel to separate the caffeine from the coffee, then used a hot …show more content…
Nevertheless, the experiment started out by needing all of our materials measured. Our group measured out 100mL of black coffee as well as 2g of sodium bicarbonate, then mixed the two together until completely dissolved in a flask. Then, to begin the caffeine extraction, we added 25mL of ethyl acetate as well as our black coffee mixture into our separatory funnel, and began to gently agitate the mixture for ten minutes. Once the time is up, we let our mixture settle in the funnel. Once there was a good portion of separating we began to drain off the leftover black coffee, and caught the caffeine extraction in a separate pre-weighed beaker. Next, we took our ethyl acetate/caffeine extraction and put it on a hotplate for the ethyl acetate to evaporate off and we were left with our caffeine extraction at the bottom of the beaker. We put the beaker and caffeine on the scale again to measure the amount of caffeine that was extracted. After that data was recorded, we added just enough ethyl acetate back into the beaker to dissolve the caffeine, and added just enough to fill our vial. Once that was done, we noted our vial numbers and sent our vials to the Gas Chromatography and Mass Spectrometry machines.
Results: Table 1: Quantitative Analysis of Caffeine.
Identity of Sample Black Coffee (caffeine) Volume of Sample Used 100mL Mass of Empty Beaker 31.345 g Mass of Beaker + Caffeine 31.263 g Mass of …show more content…
The first being, “Is the solid that was found caffeine?” and the second could be, “Was the solid found only caffeine?” Another question that could be asked is, “Is the caffeine that was found in the coffee, the same type of caffeine that is in liquids such as tea or soda?” We could use a similar procedure using the Ethyl Acetate. Our group's experiment went slightly wrong, and when we first measured the mass of our glass beaker, our initial and final masses gave us a result of -0.00082 mg. Using the extraction method using a separatory flask allowed us to see the separation of the Ethyl Acetate layer, and the water (coffee minus the caffeine) layer. The caffeine has been extracted from the coffee into the Ethyl Acetate layer because the caffeine is more soluble in Ethyl Acetate than the water (coffee minus the caffeine). We confirmed that this substance was caffeine due to the Gas Chromatography graph with one peak at 1.457 minutes. And because the Ethyl Acetate was more mobile through the mass spectrometer, that caused the caffeine to be stationary within the column. This is also proven because of the 7 peaks of caffeine in the mass spectrometer. Even with the error in our mass of the dried caffeine, these two methods of testing the caffeine showed that we tested only
Amount of Caffeine in 100mL sample of Coffee.
Introduction: Within this lab, our group was supposed to determine the amount of caffeine that was in a 100mL sample of plain black coffee. First, we created a mixture of black coffee, sodium carbonate, and ethyl acetate in an Erlenmeyer flask. We used a separatory funnel to separate the caffeine from the coffee, then used a hot …show more content…
Nevertheless, the experiment started out by needing all of our materials measured. Our group measured out 100mL of black coffee as well as 2g of sodium bicarbonate, then mixed the two together until completely dissolved in a flask. Then, to begin the caffeine extraction, we added 25mL of ethyl acetate as well as our black coffee mixture into our separatory funnel, and began to gently agitate the mixture for ten minutes. Once the time is up, we let our mixture settle in the funnel. Once there was a good portion of separating we began to drain off the leftover black coffee, and caught the caffeine extraction in a separate pre-weighed beaker. Next, we took our ethyl acetate/caffeine extraction and put it on a hotplate for the ethyl acetate to evaporate off and we were left with our caffeine extraction at the bottom of the beaker. We put the beaker and caffeine on the scale again to measure the amount of caffeine that was extracted. After that data was recorded, we added just enough ethyl acetate back into the beaker to dissolve the caffeine, and added just enough to fill our vial. Once that was done, we noted our vial numbers and sent our vials to the Gas Chromatography and Mass Spectrometry machines.
Results: Table 1: Quantitative Analysis of Caffeine.
Identity of Sample Black Coffee (caffeine) Volume of Sample Used 100mL Mass of Empty Beaker 31.345 g Mass of Beaker + Caffeine 31.263 g Mass of …show more content…
The first being, “Is the solid that was found caffeine?” and the second could be, “Was the solid found only caffeine?” Another question that could be asked is, “Is the caffeine that was found in the coffee, the same type of caffeine that is in liquids such as tea or soda?” We could use a similar procedure using the Ethyl Acetate. Our group's experiment went slightly wrong, and when we first measured the mass of our glass beaker, our initial and final masses gave us a result of -0.00082 mg. Using the extraction method using a separatory flask allowed us to see the separation of the Ethyl Acetate layer, and the water (coffee minus the caffeine) layer. The caffeine has been extracted from the coffee into the Ethyl Acetate layer because the caffeine is more soluble in Ethyl Acetate than the water (coffee minus the caffeine). We confirmed that this substance was caffeine due to the Gas Chromatography graph with one peak at 1.457 minutes. And because the Ethyl Acetate was more mobile through the mass spectrometer, that caused the caffeine to be stationary within the column. This is also proven because of the 7 peaks of caffeine in the mass spectrometer. Even with the error in our mass of the dried caffeine, these two methods of testing the caffeine showed that we tested only