EXPERIMENTAL DETAILS The analytes were the following, commonly available, colored substances: Gatorade instant powder dry mix energy drink, lemon-lime flavor; blue food coloring solution (Market Pantry, Target Corporation); and iron(III) chloride hexahydrate (Sargent Welch, reagent grade). Each substance was dissolved into water, using distilled, deionized, or tap water. The source of water did not influence the quality of the results. Serial dilutions were performed to obtain solutions ranging from "full strength" to as dilute as 0.3% of the stock solution concentration. The serial dilutions were performed using autopipets or simple graduated cylinders, depending upon the equipment available. Either standard glass test tubes or plastic cuvettes (Flinn Scientific, Inc.), with path lengths of 1 cm, were used. In the case of the blue food coloring, each solution was volumetrically added to the cuvette by way of an auto pipet, and images were collected from the side (perpendicular to the