Determination of seven synthetic dyes in animal feeds and meat by high performance liquid chromatography with diode array and tandem mass detectors.

An efficient method was developed for the simultaneous determination of seven commonly used synthetic sulfonate dyes (Ponceau 4RC, Sunset yellow, Allura red, Azophloxine, Ponceau xylidine, Erythrosine and Orange II) in animal feed and meat using high performance liquid chromatography (HPLC-DAD) and tandem mass spectrometry (HPLC-MS/MS). Ethanol-ammonia-water (80:1:19, V/V/V) solution was used as extract solution, which can extract target species while reducing interference from the sample matrices. The recoveries of these 7 dyes in animal feed and chicken meat were between 71% and 97% with relative standard deviations less than 14.8%. HPLC-MS/MS was employed as a further means of confirmation to assure accuracy of the results. Limits of detection for these dyes were in the range of 0.02-21.83 ng mL(-1). The proposed method can be applied to confirmative screening of seven commonly used food colorants in feed and meat samples.