Experiment 38 The Thin-Layer Chromatography Analysis of Cough Syrups for Dyes

Experiment 38 The Thin-Layer Chromatography Analysis of Cough Syrups for Dyes 

Note Many cough medicine formulations exhibit the color they have because a food colorant has been added. Such colorants are standard Food, Drug, and Cosmetic (FD8jC) dyes, typically blue 1 red 3, 33, and 40 or yellow 5, 6, and 10. In this experiment, identification of such dyes is accomplished by TLC. 

Weigh 10 mg of each dye standard into 50-mL volumetric flasks, dilute to the mark with distilled water, and shake. If the dye is not water soluble (Lake dyes are insoluble dyes), dissolve it directly in the n-butanol in step 3. 

Pipet 5 mL of each standard and 5 mL of each sample into separate 50-mL Erlenmeyer flasks. 

Add five drops of diluted HC1 (prepared by diluting 23.6 mL of concentrated HC1 to 100 mL in the distilled water) and 5 mL of n-butanol to each flask and shake on a shaker for 30 min. 

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