[Analytical method of organophosphorus flame retardants in fish by ultra-high performance liquid chromatography-tandem mass spectrometry based on EMR-Lipid purification].

Objective: A method for simultaneous determination of 11 kinds of organophosphorus flame retardants in fish was established by using the EMR-Lipid cleaning agent and ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).

Methods: The samples were extracted by ultrasonic with 0.5% formic acid acetonitrile solution. The lipid removal product EMR-lipid was used for lipid purification. The co-extracts were further removed by magnesium sulfate, N-propyl ethylene amine(PSA) and graphitized carbon black(GCB) purification agent. The target compounds were separated on an ACQUITY UPLC® BEH C_(18) column(100 mm×2.1 mm, 1.7 μm), detected by electrospray ionization(ESI) and positive ion multiple reaction monitoring mode, the internal standard method and external standard method are quantitatively evaluated, and external standard method was adopted.

Results: The 11 kinds of organophosphorus flame retardants had a good linear relationship in the range of 0.5-50 μg/L(tris(2-ethylhexyl) phosphate 0.05-5 μg/L) with r>0.999. The limits of detection were 0.004-1.029 μg/kg and the limits of quantitation were 0.012-3.094 μg/kg. The average recoveries at three spiked levels(low, medium and high) were 80.0%-111.2% with the relative standard deviations all less than 10%(n=6).

Conclusion: The method could be used for the determination of trace organophosphorus flame retardants in freshwater fish with accurate and reliable result.