Simultaneous Determination of Fifteen Illegal Dyes in Animal Feeds and Poultry Products by Ultra-high Performance Liquid Chromatography Tandem Mass Spectrometry

With the increasing presence of illegal dyes, such as sudan reds and malachite green, in animal feeds and food products during the last few years, there is an urgent need of accurate quantitative determination methods for these illicit compounds. Here we established an accurate method for the simultaneous determination of 15 illegal dyes in animal feeds, meat, eggs and other food products using ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The samples were extracted with a simple procedure using acetonitrile and solid phase extraction cleaning up. The application of C(18) rapid column can achieve satisfactory separation of the 15 dyes within 16 min; and multiple reaction monitoring of positive ions ensure confirmative detection of these illegal dyes. With the developed method, a sample can be analyzed in less than 2h. Dyes spiked in feeds, poultry meat and eggs in the range of 0.1-5.0 mg kg(-1) were tested in terms of linearity, sensitivity, repeatability and recovery. Recoveries for the compounds ranged from 60 to 140%. Intra- and inter-day precisions (RSDs) were less than 15%. Limit of quantification ranged from 0.01 to 5.61 μg kg(-1) for different dyes. The developed UHPLC-MS/MS method could be used as a qualitative and quantitative technique for the simultaneous determination of illegal dyes in animal feeds and poultry products.