分散固相萃取结合高效液相色谱串联质谱测定食品接触用纸中的6种季铵盐抑菌剂

建立了基于分散固相萃取的高效液相色谱-串联质谱法用于同时测定食品接触用纸中的6种季铵盐类抑菌剂。该方法集萃取和净化于一体，样品在超声辅助下经甲醇提取，N-丙基乙二胺（primary secondary amine，PSA）净化后过有机膜即可上机分析。用Brownlee SPP C₁₈柱分离，5 mmol/L乙酸铵水溶液和5 mmol/L乙酸铵甲醇溶液为流动相进行梯度洗脱，电喷雾正离子多反应监测模式扫描，外标法定量。结果显示:目标物在0.5~100 μg/L质量浓度范围内线性相关系数r>0.9987，检出限为0.2~0.4 μg/kg，定量限为0.8~1.0 μg/kg。三种添加水平下的回收率为79%~113%，精密度小于8.9%。该方法操作简便，灵敏度高，适用于食品接触用纸中6种季铵盐类抑菌剂的检测。

Determination of Six Quaternary Ammonium Bacteriostatic Agents in Food Contact Paper by Dispersive Solid Phase Extraction Combined with High Performance Liquid Chromatography-tandem Mass Spectrometry

A high performance liquid chromatography-tandem mass spectrometry method based on dispersive solid phase extraction was established for the simultaneous determination of six quaternary ammonium bacteriostats in food contact paper.The method integrates extraction and purification,the sample was extracted with methanol under the assistance of ultrasound.Purified by PSA and filtered through organic membrane,the sample could be analyzed by HPLC-MS/MS.Separated by Brownlee SPP C₁₈ column,5 mmol/L ammonium acetate aqueous solution and 5 mmol/L ammonium acetate methanol solution were used as the mobile phase for gradient elution,electrospray positive ion multi-reaction monitoring mode scanning,external standard method for quantification.The results showed good linearity was achieved for the target analytes in the concentration range of 0.5~100μg/L.The linear correlation coefficients of the calibration curves for the compounds were greater than 0.9987.The limit of detection was 0.2~0.4μg/kg and the limit of quantification was 0.8~1.0μg/kg.The average recoveries at the three levels of addition were 79%~113%,the precision was less than 8.9%.The method is easy to operate and has high sensitivity,which is suitable for the detection of six quaternary ammonium bacteriostats in food contact paper.