Determination of PFOS and PFOA in Food Matrix of Animal Origin Using UHPLC Hyphenated Triple Quadrupole Tandem Mass Spectrometry* Authors

An ultrasensitive method has been developed for simultaneous determination of perfluorooctane sulfonates (PFOS) and perfluorooctanoic acid (PFOA) in food using an Agilent UHPLC 1290 hyphenated Triple Quadrupole 6460 tandem mass spectrometer. The samples were first extracted using methanol, followed by cleanup with weak anion-exchange cartridge. The resultant solutions were subjected to reversephase UHPLC separation and triple quadrupole MRM detection. The dynamic linear range for PFOA and PFOS was 0.01–10 ng/mL and 0.1–40 ng/mL, respectively, with linear correlation regression coefficient of 0.999 or above. The limit of detection (LOD) (signal-to-noise (S/N) = 3) was 0.002 and 0.02 μg/kg for PFOA and PFOS, respectively, and the limit of quantitation (LOQ) (S/N=10) was 0.01 and 0.1 μg/kg, respectively. The average spiking recoveries at three levels in the matrix of fish, shrimp, and eggs ranged from 79.2% to 113.1%, with the relative standard deviation (RSD) within 3.2–10.7% (n=6). Inter-laboratories validation further proves the accuracy and reliability of the method. The developed method has the advantages of high sensitivity, high recovery, and good selectivity. Therefore, it can be applied for routine inspection of PFOA and PFOS in food of animal origin. *The primary work has been presented in the China Annual National Conference of Organic Mass Spectrometry in 2012.