The objective of this lab is to isolate lycopene from tomato paste using extraction techniques practiced in perious labs then, an analysis will be conducted on the purity of the compound based on other students results and various forms of analysis. The purpose of this lab is to use what we know about the compound with extraction techniques practiced to come up with our own procedure to conduct the isolated compound and proper analysis of it.

What procedure will you use to isolate the lycopene from your tomato paste? As part of your procedure, you need to exactly specify the solvent system you will use to prepare the paste and the amount of each solvent(s).  You will use 12 grams of tomato paste which is about the equivalent of 3 g of dry material. 

1. Weigh 12 grams of tomato paste in a round bottom flask.

2. Add 40 mL of 3:1 ratio hexane/ethyl ethanol.

3. Allow the solution to refulx for about 75 minutes or until two distinct layers are present.

4. Transfer the solution to a seperatory funnel where two layers should settle and be present. Add 10 mL of water to fully extract the compound into the non-polar organic layer.

5. The bottom layer should be the polar layer while the top should be the organic layer with the compound of intrest.

6. Drain the layers to extract the non-polar organic layer.

7. Dry the solution with an anhydrous sodium sulfate until the mixture swirls.

8. Vaccum filter the anhydrous salt out of solution then evaporate until solid lycopene is formed.

9. Analyze the compound using TLC, UV/vis, and comparisons to other groups compound to determine purity.

Weighed 12.06 grams of tomato paste.

Transfered into a round bottom flask.

Measured 62mL of a solvent solution with 3:1 hexane/ethanol

Placed the round bottom flask in a heating mantle and placed in a reflux setup with the mantle at 30% heat.

The solution boiled for about 40 minutets, the solution was a dark red color.

Once removed from heat, the solution was vaccum filtered and placed inot a seperatotroy funnel, two layers were present.

10 mL of DI water was also added ot the seperatortoty funnel to create distinction of the two layers.

The aqueous layer was extracted first and the non-polar organic layer was extarcted second.

Anhydrous sodium sulfate was added to remove any remaging water from the non-polar organic extract.

The solution was then placed on a hot plate until the solvent evaporated, red paste was on the bottom of the flask.

The flask with lycopene was weighed to be 112.65 grams.

The remaining solid in the flask was scrapped.

The flask was weighed after the lycopene was removed to be 112.46 grams.

A TLC analysis was conducted with a 9:1 hexane/ethyl acetate solvent.

UV/vis

About 0.3 grams of lycopene was dissolved into 3 mL of ethanol and placed into a cuvette(Light yellow color).

3mL of pure ethanol was placed into a cuvette placed into the UV/vis machine to act as the standard and to be zeroed.
Once the machine was set to zero, the cuvette containing the isolated lycopene dissolve din ethanol was put into the machine and the read button was clicked.

Absorption was collected relaive to the standard of pure ethanol.

Mass Spectrometry

refer to lab 7 for details on mass spectrometry

Mass recovery: 0.19 grams

% yeild = 0.19g/12 g * 100% = 1.6%

Through the process of reflux and extraction, a total of 0.19 grams of wet lycopene were extracted making for a 1.6% mass recovery yield. According to the details of the lab and rubric, a good yield is about 0.2 grams wet making this experiment successful in the recovery of an organic material. The goal of the lab was to extract lycopene from tomato paste. Looking at the various forms of analysis, I'm fairly confident that our group successfully isolated lycopene. On the various TLC plates from different groups within the lab, the Rf values are very similar ranging from 0.44-0.51. Although I'm confident lycopene was within the extracted material, I also think the material was contaminated as each group had a variety of spots which could've been other materials and had an effect on the Rf values present. The isolated compound moved as predicted considering the solvent was mostly non-polar and lycopene is a non-polar compound. From a qualitative perspective, each group isolated an orange/red substance which is the correct color of lycopene as lycopene contributes to the red color of the tomato. Each group extracted a variety of substances but with similar Rf values and colors, I can assume the

Analyzing the results of the UV/vis, our extracted substance was tested to have 0.2805 abs and 500 nm. Literature values from Science Direct state that lycopene has a wavelength of 450-470 nm. The wavelength determined from UV/vis analysis fits within this range further increasing my confidence that the substance analyzed was lycopene. This analysis was also very similar to Violet and Sebastian who have peaks between 400-500 nm.

Another step of analysis my group took was mass spectrometry. The mass spec machine showed a peak present at 491.36 g/mol while the expected mass for lycopene was said to be 536.8 g/mol. This further shows that contamination was present or a slight inefficacy took place during the extraction and isolation of the intended compound.

Overall, this lab was successful in isolating the compound of interest using new extraction techniques. I learned about refluxing and how to use it to isolate a compound from an organic substance. If I were to repeat this lab, I would reflux for longer to try and further isolate lycopene and see how that would change the results and if only one spot would be present in the TLC analysis. I got to practice UV/vis as a form of analysis and see how that further supported or debunked the purity of my extracted substance.