Polymer and Materials Science
Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
Controlled adsorptive accumulation of the food additives (azo dyes) ponceau 4R, Allura Red, and carmoisine at a hanging mercury drop electrode (HMDE) provided the basis for their determination by stripping voltammetry at nanomolar concentration levels. The adsorptive stripping response was evaluated with respect to experimental parameters such as accumulation potential, preconcentration time, pH, and bulk concentration. Best results were obtained using an ammonia buffer as the supporting electrolyte; depending on the dye, detection limits of 0.071, 0.076, and 0.043 nM were, respectively, achieved in pure dye solutions. The simultaneous determination was carried out by means of the generalized standard addition method.
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