Determination of Zearalenone and Its Metabolites in Milk Powder by HPLC-MS/MS with QuEChERS Cleanup

A method for simultaneous determination of zearalenone and its metabolites(ZERs)in milk powder was developed by high performance liquid chromatography-tandem mass spectrometry with QuEChERS cleanup. The sample was diluted with 10 mL ultra-pure water,extracted by 1% acetonitrile acetate,and sodium acetate salting out,cleaned up with C₁₈,PSA and mgnesium sulfate anhydrous. The analytes were separated by a reversed phase C₁₈ column and gradiently eluted with 5 mmol/L ammonium acetate and acetonitrile. The determination was conducted by negative electrospray ionization(ESI-)with the multiple reaction monitoring(MRM)mode. The ZERs was quantified by internal standard method with β-zearalenol-d7. The good linearities were obtained for ZERs at the concentration of 0.1~50 μg/L with the linear correlation coefficients more than 0.999,and the matrix effect was inhibition. The limits of detection(LOD)and the limits of quantification(LOQ)for ZERs were 0.1 μg/kg and 0.2 μg/kg,respectively. The recoveries at three concentration spiked levels were in the range of 85.2%~119.3%. The repeatability expressed as relative standard deviations(RSD)was ranged from 0.3% to 12.2%(n=7). The method is simple,rapid,accurate and reliable,and can be used for detecting ZERs in milk powder.