Simultaneous determination of six perfluorinated organic compounds in feed by using polyamide solid-phase extraction with ultra performance liquid chromatography-tandem mass spectrometry

Abstract

A method for the determination of six perfluorinated organic compounds (PFCs) in feed has been developed. It is based on polyamide solid-phase extraction (SPE) together with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The sample was extracted by acidified acetonitrile. The extraction solution was enriched by a polyamide SPE cartridge under acidic condition, and cleaned-up using methanol, eluted by 5% (v/v) ammonia/methanol solvent and determined by UPLC-MS/MS. The UPLC separation was carried out on an Acquity BEH C18 column (100 mm x 2.1 mm, 1.7 microm). The mobile phases were 5 mmol/L ammonium acetate and acetonitrile with a gradient elution. Under the optimal conditions, the PFCs were analyzed under multiple reaction monitoring (MRM) mode with negative electrospray ionization. The isotope internal standard method was used to determine the six PFCs, and improve the quantitative accuracy. All of the target compounds exhibited good linearity (r > 0.995) over a concentration range of 0.5-25 microg/L. The detection limits of the six PFCs were all smaller than 0.1 microg/kg. The mean recoveries of the six PFCs were in the range of 94.2% to 108.9% with the relative standard deviations (RSDs) of 1.8% - 8.6% (n = 6). The method for the determination of PFCs in feed is low-cost, favorable effect and suitable for the detection of complex matrix samples.