| A high performance liquid chromatography-mass spectrometric(HPLC-MS) method was established for the simultaneous determination of five trace preservatives in beer.The sample was heated in water bath,cleaned up with a C18 solid phase extraction column,and then analyzed under parent ion monitoring mode.Matrix-matched calibration curve was used to determine the trace contents by external standard method.The method showed good linearities in the range of 0.1-10.0 mg/L for five targets,with correlation coefficients more than 0.99.The recoveries at three spiked concentration levels ranged from 62.2% to 125.0%,with RSDs of 0.14%-3.4%.The limits of detection（LODs） for benzoic acid and sorbic acid were 0.020 mg/L and 0.015 mg/L,and the limits of quantitation（LOQs） were 0.060 mg/L and 0.050 mg/L,respectively.While the LODs of three parabens were all 0.010 mg/L and the LOQs were all 0.045 mg/L.With good purifying effect,sensitivity,recovery and repeatability,the developed method is suitable for the determination of preservatives in beer for sales. |