Simultaneous determination of synthetic dyes in foodstuffs and beverages by high-performance liquid chromatography coupled with diode-array detector

Abstract

Abstract Synthetic dyes are added to food and drinks to restore their original appearance when color is affected by processing, storage, packaging and distribution. Furthermore colors are used to make food more visually attractive to consumers. The EU Directive 1994/36/CE lists the permitted substances that can be used in foodstuffs. In order to investigate the content of some permitted and non-permitted dyes in food and drinks, a sensitive and helpful method has been developed to determine simultaneously seventeen synthetic colorants by high-performance liquid chromatography coupled with a diode-array detector in solid food matrices and beverages. Substances involved were azorubine (E122), amaranth (E123), cochineal red A (E124), red 2G (E128), allura red (E129), azocarmine B (AZO B), azocarmine G (AZO G), ponceau 2R (P2R), ponceau 6R (P6R), tartrazine (E102), sunset yellow (E110), quinoline yellow (E104), orange II (OR II), metanil yellow (MY), patent blue V (E131), indigo carmine (E132) and brilliant blue FCF (E133). Solid food matrices were extracted by a water–alcohol mixture, cleaned up on a polyamide SPE cartridge and eluted with basic methanol solution. Otherwise a simple dilution and filtration of samples were used for drinks. The method has been validated according to Regulation (2004/882/CE) and could be applied to a concentration range between 5 and 300 mg kg−1 (5–100 mg l−1 for drinks) depending on the dye. The accuracy (precision and trueness) and specificity were assessed. During years 2009–2011 many food samples for the detection of synthetic colorants were analyzed. Most of them were fresh fishery products in which the use of food colorant is banned.