A simple spectrophotometric procedure for the quantitative determination of FD&C food dyes in powdered drink mixes appropriate for high school or general science classes is presented. This method describes the determination of the total quantity of food dye, the quantity of dye per serving, and the percent by mass of each dye in the sample. Directions for the creation of food dye calibration curves is also presented. Lab time required is two–three hours.
Supplement
Two separate student experiments are described. The first is a basic experiment where students determine the mass of each dye directly from the measured absorbance values using equations. The second experiment involves the creation of calibration curves using food coloring available at local grocery stores. Students use the measured absorbance and the calibration curve to determine the mass of dye in each sample. Extensive notes for instructors, detailed directions for sample preparation, and instructions for the construction of calibration curves are available. Directions for students, data tables, and calculation equations are also provided.
Contents
JCE2004p1475W.doc (Microsoft Word)
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Citation
Sigmann, Samuella B.; Wheeler, Dale E. J. Chem. Educ.2004 81 1475.
Keywords
Aqueous Solution Chemistry; Dyes/Pigments; Food Science; General Chemistry; Introductory / High School Chemistry; Laboratory Instruction; Quantitative Analysis; UV-Vis Spectroscopy
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