Seven Drops Procedure

The procedure provided was used with only one change and one correction. The procedure calls for 3 or 4 drops of water to dissolve the dye on the M&M candies but 7 drops were used for each pair of candies because there wasn’t enough water in 4 drops to efficiently dissolve the dyes; the YouTube video for this step from the procedure also showed an application of about 7 drops. The traced solvent front line in this case was not a straight line but a curve with a maximum on 3.2in and minimum on 2.48in it was instructed to take the average and use it as our solvent front. Different compounds absorb with different strengths depending on their ability to dissolve in the eluent and temperature. The distance that a spot moves up on chromatography paper is used to characterize the absorption of that substance.
A low distance means the molecules are absorbed to the stationary phase; the cellulose in the chromatography paper more than the solvent. The fraction of time spent in the mobile phase is the Rf value. Example- For the red candy there is one spot. Measuring from the middle of the spot to the spotting line the distance is .5cm this is the distance moved by the substance. The distance moved by the mobile phase is the solvent front in this case 7cm; the distance the solvent moved up the paper before removing the paper from the eluent. The Rf value = .5cm/7cm = 0.071. The result is a unit less ratio between the spot distance and solvent front. The brown and green M&M candies contain more than one dye, the brown M&Ms have red, yellow and blue dyes, the green M&Ms have yellow and blue