Dual-wavelength Ratio Spectrometric Determination of Carmine, Sunset Yellow and Tartrazine in Beverages

DU Jian-zhong1,LI Qing-mei1,ZHU Yi-qiang1,DING Ding2,3,TAN Yong-hui1 (1. Development Center for New Materials Engineering and Technology in Universities of Guangdong, Zhanjiang Normal University, Zhanjiang 524048, China;2. Graduate School of Public Health, San Diego State University, San Diego 92123, USA; 3. Department of Family and Preventive Medicine, University of California, San Diego, San Diego 92137, USA)

dual-wavelength ratio;carmine;sunset yellow;tartrazine;bevevage

A dual-wavelength ratio spectrometric method was presented for the determination of carmine, sunset yellow and tartrazine in fruit-flavored carbonated beverages. According to the spectral characteristics of the pigments, the wavelengths were chosen to be 431 nm and 456 nm for tartrazine detection and 509 nm and 525nm for carmine detection under the disturbance of sunset yellow and 514 nm and 535 nm for sunset yellow detection under the disturbance of carmine. Results showed that the developed standard curves for determining carmine, sunset yellow and tartrazine all exhibited good linearity over the concentration ranges of 0.2 to 80, 0.8 to 90 mg/L and 0.1 to 60 mg/L, respectively. The mean recoveries of 5 replicates of carmine, sunset yellow and tartrazine in orange-flavored Miranda soft drink were 100.5%, 101.1% and 102.4% respectively. This method proved to be simple and convenient and thus deserves to be popularized.