Abstract: A method for the simultaneous identification and quantification of thirteen perfluoroalkyl carboxylic acids (PFCAs), six fluorotelomer saturated carboxylic acids (FTCAs) and three fluorotelomer unsaturated carboxylic acids (FTUCAs) in bivalve shellfish tissues was developed using ultra fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS). Samples were extracted with acetonitrile-water (90:10, V/V), and the extract was cleaned up by solid-phase extraction (SPE) using Oasis WAX SPE coupled in-line to ENVI-Carb. Then, the separation was performed on a Kinetex XB-C18 column (2.1 mm × 100 mm, 2.6 μm) with gradient elution using a mixture of 95% methanol solution containing 5 mmol/L ammonium acetate and 5% methanol solution containing 5 mmol/L ammonium acetate as the mobile phase. Mass spectrometry was carried out under the multiple reaction monitoring (MRM) mode with negative electrospray ionization and the internal standard method was employed for quantification. The calibration curves for 22 analytes were linear well with correlation coefficient over 0.995. The limits of quantification ranged from 0.03 to 1.67 ng/g. The average spiked recoveries for 22 analytes were between 63.05% and 127.18%, with relative standard deviations (RSDs) from 4.70% to 17.1%. This method was successfully applied for the simultaneous determination of 13 PFCAs and 9 potential precursors in bivalve shellfish tissue samples.

Key words: perfluorinated acids and their precursors, bivalve shellfish, solid-phase extraction (SPE), ultra fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS)