Chromatography of Food Dyes

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Experiment 11 Lab Assignment Answer Sheet: Chromatography of Food Dyes Name: Pre-Lab: Define the Rf value of a compound: It is the distance traveled by the compound divided by the distance traveled by the solvent front. Data and Observations: Record the distance travelled by the sample and the solvent in the table below and calculate the Rf values. Table 1. Color|Blue1|Blue2|Red3|Red40|Yellow5|Yellow6|Solvent| Distance(mm)|50mm|0mm|10mm|21mm|28mm|23mm|50mm| Rf|1|0|0.2|0.42|0.56|0.46|1| Table 2. Substance|Kool-Aid®: Grape|Kool-Aid®: Strawberry|Solvent| Distance (mm)| 19mm(red)|28mm(red)|48mm| Distance (mm)| 47mm(blue)||48mm| Rf|0.39 & 0.98|0.58|1| Table 3. Substance|Store Red|Store Yellow|Store Green|Store Blue|Solvent| Distance (mm)|33mm|30mm|34mm(yellow)|50mm|50mm| Distance (mm)|||50mm(blue)||50mm| Rf|0.66|0.60|0.68 & 1|1|1| Table 4. Substance|M&MBrown|M&M Yellow|M&MBlue|M&MRed|Solvent| Distance (mm)|20mm|25mm|5mm|13mm|50mm| Rf|0.40|0.50|0.10|0.26|1| A. The FD&C color(s) making up the unknown = Red and Blue. B. Brand name of the FD&C color(s) from the grocery store food = Market Pantry C. The FD&C color(s) making up the grocery store food colorings = Red #40, Blue #1, Yellow #5, Yellow #6. D. The FD&C color(s) making up the Kool-Aid drinks. = Red #40 and Blue #1. E. The FD&C color(s) making up the M&M’s®. = Yellow #6, Yellow #5, Red #40, Blue #1, Blue #2. Post-Lab Questions: 1.Why can't a pen be used to draw the baseline on the chromatography paper? Because the ink would bleed as well and might contaminate the results. 2. Why is it important to stop the chromatograph before the solvent reaches the top of the paper ? Because if the solvent gets to the top, I could miss the measuring points because they would keep moving. 3.Why is

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