Determination of Sudan Red I–IV in Duck Egg Yolk Using Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

A method of simultaneous analysis of Sudan Red I–IV in duck egg yolk was developed using ultra performance liquid chromatography-tandem quadrupole mass spectrometry (UPLC-MS/MS). The Sudan Red I–IV were extracted with acetonitrile from duck egg yolk. Impurities, such as, protein and fat, were precipitated from the extraction with the addition of water. After refrigeration and centrifugation, the upper layer was collected for UPLC-MS/MS analysis. The UPLC-MS/MS was carried out on a Waters Acquity BHE C18 column with the tandem quadrupole mass spectrometer in the multiple reaction monitoring (MRM) mode. The limits of detection (LODs) for all four substances in the standard solution were 0.05 μg/L, and the LODs for all four substances, spiked in practical samples were 10 μg/kg. The average recoveries for spiked samples at three spiking levels, 100, 200, and 300 μg/kg, were in the range of 50.2%–101.3%. The experimental results indicated that this method had the advantages of high sensitivity, low LOD, good capability of identification for Sudan Red, and needed a short time for analysis. It met the requirement of the high-throughput detection of Sudan Red in daily food samples.