Direct Solid-phase Spectrophotometric Determination of Tartrazine in Soft Drinks Using β-Cyclodextrin Polymer as Support
RONG LI, ZI-TAO JIANG* AND YUN-HAO LIU
College of Biotechnology and Food Science, Tianjin Key Laboratory of Food Biotechnology, Tianjin University of Commerce, Tianjin 300134, P. R. China
(Received: November 28, 2007; Accepted: March 24, 2008)
ABSTRACT
A sensitive and new solid-phase spectrophotometry for the determination of tartrazine in soft drinks has been developed. In this method, β-cyclodextrin epichlorohydrin polymer (β-CDP) of 60-80 mesh, which has less background absorbance in ultraviolet and visible region compared to other ion-exchanger resins, was used to support direct adsorption of tartrazine from aqueous solutions to form a solid complex (tartrazine-β-CDP complex). The effects of pH, temperature, time and ionic strength on the β-CDP including tartrazine were determined. The optimum conditions were obtained (pH, 1.0; temperature, 20°C; time, 40 min). The method was applied for the direct solid phase spectrophotometric determination of tartrazine in soft drink samples at the maximum absorption wavelength of 435 nm with satisfactory results.
Key words: Tartrazine, solid-phase spectrophotometry, β-cyclodextrin epichlorohydrin polymer (β-CDP)