Method validation of 12 kinds of food dye in chewing gums and soft drinks, and evaluation of measurement uncertainty for soft drinks

Abstract We developed and validated a method for the simultaneous quantitative analysis of food dyes in two food matrices, i.e., chewing gum and soft drinks. Furthermore, we evaluated the stability of food dyes in these matrices with respect to the pH and acid content. The optimized and validated method is based on high-performance liquid chromatography–photodiode array (HPLC-PDA) and liquid chromatography–tandem spectroscopy; the proposed method could identify and quantify 12 dyes in the two matrices. The recoveries of the food dyes identified by HPLC-PDA analysis ranged from 98.61% to 118.42%, with relative standard deviations of 0.06–4.90%. In addition, the expanded uncertainties of the measurements ranged from 0.57 to 3.12%. Finally, the food dyes were found to be stable in the matrices over 30 days. Thus, we believe that the proposed analytical method is suitable for the identification and quantification of food dyes in chewing gum and soft drink samples.