Acetone Hexane Lab Report
Pigments were first extracted from tomato paste by a 50/50 mixture of acetone/hexanes; these miscible molecules act together as one organic solvent. Pigments choose the organic layer over the tomato paste with water, which allowed for their extraction. K2CO3 is an ionic base that was added to deprotonate the citric acid. The ionic product of the reaction in figure 3 now prefers the aqueous layer, which serves to wash the pigments of the acidic impurity. Saturated NaCl pulls any water into the aqueous layer. MgSO4 was used as a drying agent to evaporate off the 50/50 acetone/hexane organic solvent. A rotovap was then used to concentrate the solution to dryness.
When packing the chromatography column, cotton is added to prevent the …show more content…
The non-polar eluent 100% hexane was used to elute the less polar pigment beta-carotene, which was light yellow. The second eluent was 90% Hexane/10% acetone. Acetone H bonds to take spots on the stationary alumina, which forces the more polar pigment lycopene out of the column, which was a dark orange color. Reversing order of eluents would make both pigments come out at the same time. While Lycopene and beta-carotene have the same number of double bonds lycopene has all trans double bonds, which have better P orbital alignment, and hyperconjugation. There was quite a bit of space between the two pigments in the column, making for a successful separation. TLC can be used to check …show more content…
This prevented the second wash from fulfilling its purpose of taking out extra water particles. This decreases the quality of the extraction. I also diluted the final pigments in the round bottom flask with 5 mL of hexanes instead of 0.5 mL. That diluted the sample, making the pigments in the column less bright and the colors of the extracted solutions light yellow instead of yellow for beta-carotene and red-orange instead of red for lycopene. The total amount of pigment extracted was also decreased since not all of the 5 mL of hexanes and pigment could be added to the column. Another error occurred when stopping suctioning and some of the whole column was pulled up forming a crack of air. This prevented an even diffusion of the pigments down the column and disrupts
When packing the chromatography column, cotton is added to prevent the …show more content…
The non-polar eluent 100% hexane was used to elute the less polar pigment beta-carotene, which was light yellow. The second eluent was 90% Hexane/10% acetone. Acetone H bonds to take spots on the stationary alumina, which forces the more polar pigment lycopene out of the column, which was a dark orange color. Reversing order of eluents would make both pigments come out at the same time. While Lycopene and beta-carotene have the same number of double bonds lycopene has all trans double bonds, which have better P orbital alignment, and hyperconjugation. There was quite a bit of space between the two pigments in the column, making for a successful separation. TLC can be used to check …show more content…
This prevented the second wash from fulfilling its purpose of taking out extra water particles. This decreases the quality of the extraction. I also diluted the final pigments in the round bottom flask with 5 mL of hexanes instead of 0.5 mL. That diluted the sample, making the pigments in the column less bright and the colors of the extracted solutions light yellow instead of yellow for beta-carotene and red-orange instead of red for lycopene. The total amount of pigment extracted was also decreased since not all of the 5 mL of hexanes and pigment could be added to the column. Another error occurred when stopping suctioning and some of the whole column was pulled up forming a crack of air. This prevented an even diffusion of the pigments down the column and disrupts