Procedure

1.      Use a 10-mL syringe, a dropper bottle, or a wash bottle as a solvent pump to flush the C18 Sep-Pack cartridge with 10 mL of undiluted 18% isopropanol at a rate of 5 to 10 mL per minute.

2.      Collect the eluate in a 10-mL graduated cylinder to monitor the flow rate of the isopropanol.

3.      Using the 10-mL syringe, flush the Sep-Pack cartridge with 10 mL of distilled water.

4.      Draw up 1 mL of the grape Kool-Aid sample with the 1-mL syringe.

5.      Slowly inject the Kool-Aid sample into the Sep-Pack cartridge.

6.      Collect and discard the effluent that washes out of the column as you inject the sample.

7.      Fill the solvent pump (10-mL syringe) with 18% isopropanol solution.

8.      Pump the solvent through the Sep-Pack cartridge at a steady rate of 5 to 10 mL per minute.

9.  Collect the eluent in the 10-mL graduated cylinder.

10.  Record (in Table 2) the volume of liquid in the graduated cylinder when the red or blue dye is first observed in the eluent from the Sep-Pack column  and when that color is no longer observed .