Are the food colorings used in colored candy the same as the the FD&C approved chemicals?
How many colored spots do you expect to see for each reference standard?
- Obtain a 25 cm square piece of chromatography paper that will fit into the beaker that will serve as the chromatography chamber.
- Draw a pencil line across the lower end of the chromatography paper about 2 cm from the bottom.
- Draw additional vertical tick marks along this line every 2 cm
- Place colored candy in a flask with 2 ml ethanol until the color dissolves into the solution
- Using an applicator, create a very small spot on a tick mark and allow to dry
- repeat application on the spot to make a very small and dark spot
- Continue to spot reference standards along other tick marks. These reference standards are food coloring.
- place approximately 1 cm of mobile phase solution (a very polar salt water solution) into the beaker
- roll the filter paper into a cylinder and fix with staples
- place cylinder into the beaker and cover for 20 minutes or until the mobile phase reaches 2 cm from the top of the paper.
- Mark the final distance of the mobile phase and dry the filter
- Measure the distance of each spot from the starting point
- Each spot is a separate analyte.
- Some spots separate into multiple analytes.
- Measure EACH one
- Measure the distance from the starting point to the final point that the solvent reached.
- Calculate Rf values and tabulate results.
Tags: quantitative reasoning, guided inquiry