Abstract: Objective To establish an analytical method for simultaneous determination of eight fluorescent whitening agents （FWAs） in flour using ultra performance liquid chromatography-tandem mass spectrometry. Method The target compound in flour samples were extracted with acetonitrile by vortex ultrasound method. 2 mmol/L ammonium acetate（plus 0.1% formic acid） buffer and acetonitrile were used as mobile phase for gradient elution,and the target compounds were separated by Phenomenex Kinetex C₁₈（100 mm×2.1 mm,2.6 μm）.The multiple response monitoring（MRM） was selected in the positive electrospray ionization mode to quantitatively analyze eight FWAs,and the target compounds were quantified by matrix-matched external standard method. Results A good linear relationship among 8 FWAs in the range of 0.10-100 μg/L,with a correlation coefficient（r） ≥0.99. The detection limit and quantitation limit of FWA184 were 0.01 and 0.05 μg/kg.The detection limit and quantitation limit of FWA162,FWA185 and FWA367 were 0.03 and 0.10 μg/kg.The detection limit and quantitation limit of FWA140,FWA199,FWA378 and FWA393 were 0.05 and 0.20 μg/kg.The average recoveries of the method were in the range of 82.4%-113.7%,and the relative standard deviations ranged from 1.1% to 6.2% at three spiked levels. Conclusion The established method is simple,fast,accurate and covers a wide range of FWAs,making it suitable for the determination of 8 types of FWAs in flour.

Key words: Fluorescent whitening agents, Flour, Ultra performance liquid chromatography-tandem mass spectrometry