Simultaneous determination of synthetic colorants in yogurt by HPLC.

This article reports on a method to determine synthetic dyes in yogurts and milk drinks. Initially a method for extraction of artificial dyes was developed to pretreat samples in order to extract most of the artificial colorants. Then, the colorants were analyzed by HPLC-PAD using gradient elutions. The method was linear in the range of 0.5-25mgL(-1) colorants (0.9991<R(2)<0.9998), with LOD of 0.18-4.58μgL(-1). The results recovery test on two levels ranged from 82% to 115%. The reference solution of the analytes remained stable for 3months. In the yogurt samples analyzed, the dye E122 (1.4-11.75mgL(-1)) was found in most samples, followed by dye E123 (3.12 and 12.56mgL(-1)). All samples had concentrations below the maximum level allowed for use in yogurt (5-30mg/100g dyes). [corrected].