Abstract: An analytical method based on ultra-high-performance liquid chromatography-tandem mass spectrometry was developed for the simultaneous detection of 9 commonly used quaternary ammonium compounds (QACs) in various food matrices including vegetables, fruits, and aquatic products. The enrichment and purification of QACs were achieved using an improved QuEChERS method, and the separation was performed on a BEH C18 column (100 × 3.0 mm, 1.7 μm) via gradient elution. QACs were detected with electrospray ionization mass spectrometry in positive ion mode. The limits of detection and quantification for 9 QACs in vegetables, fruits, and aquatic products were 0.2-5.0 μg/kg and 1.0-10.0 μg/kg, respectively. The method showed good linearity (r2 > 0.99) within the detection range of respective QACs. The spiked recoveries were 65.24-118.63% with relative standard deviations (RSDs) of 0.19-6.77%. The method was subsequently used to study the QACs residue in commercial food and dietary samples in Beijing. The detection rate of commercial food and dietary samples was 30.43% and 12%, respectively. The result of dietary intake risk assessment showed that the risk of QACs residue is acceptable.

Key words: QACs, QuEChERS, UPLC-MS/MS, dietary intake, food safety