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 C₁₈column, 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 0.5~100 μg/L.The linear correlation coefficients of the calibration curves for the compounds were greater than 0.9987. The limit of detection was 0.2~0.4 μg/kg and the limit of quantification was 0.8~1.0 μg/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.