Determination of Bisphenol A and Bisphenol S in Egg Powder by Ultra-High Performance Liquid Chromatography Tandem Mass Spectrometry

A method for the determination of BPA(bisphenol A)and BPS(bisphenol S)in egg powder with ultra-high performance liquid chromatography tandem mass spectrometry was established. The target compounds were extracted by acetonitrile from the aqueous solution of egg powder. The removal of lipid in the sample matrix was accomplished by the usage of the dSPE-EMR-Lipid(dispersive Solid-Phase Extractions Enhanced Matrix Removal Lipid),following by the further purification with an Oasis PRiMe HLB column. The contaminant was confirmed by ultra-high performance liquid chromatography coupled with tandem mass spectrometry and the concentration was determined by internal standard method. The tandem mass spectrometry was performed in the negative electro spray ionization model and the multiple monitoring model. The results showed a good linear in the range of 1~50 μg/kg for BPA with the corresponding correlation coefficient 0.9991.The recovery rate for the spiked samples ranged from 98.8% to 105.0% with relative standard deviation 3.84%~8.58%(intra-day)and 5.65%~8.74%(inter-day). The limitation of detection for BPA was 0.3 μg/kg and 1.0 μg/kg,respectively. While results showed a good linear in the range of 0.4~20 μg/kg for BPS with the corresponding correlation coefficient 0.9995.The recovery rate for the spiked samples ranged from 98.5% to 102.5% with relative standard deviation 3.01%~7.86%(intra-day)and 3.18%~7.03%(inter-day). The limitation of quantitation for BPS was 0.1 μg/kg and 0.3 μg/kg,respectively. The concertation of compounds in actual samples was in the range of 2.4~3.8 μg/kg for BPA and 0.48~0.82 μg/kg for BPS respectively. The method was suitable for the daily investigation of BPA and BPS in the egg powder with the following advantages:simple sample pretreatment and high sensitivity.