Development of a new matrix-certified reference material for accurate measurement of PFOA and PFOS in oyster meat powder

Bioaccumulation of PFOA and PFOS in aquatic organisms is increasingly a global environmental problem. The development of biota matrix certified reference materials (CRMs) for PFOA and PFOS is urgently needed to cope with food safety supervision by assuring accurate analysis results. This paper addresses this urgent need by developing a new oyster matrix CRM of PFOA and PFOS; the certified values and expanded uncertainties are 5.63 ± 0.35 and 3.08 ± 0.20 µg/kg. The CRM candidates were prepared by adding PFOA and PFOS into raw oyster meats, followed by freeze-drying, grinding, blending, homogenizing, bottling, and gamma-irradiation. The sample pretreatment strategy of extraction and clean-up was optimized to minimize matrix effects and interferences. The isotope dilution high-performance liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) strategies were employed for certification, homogeneity, and stability assessment. In addition, uncertainties were evaluated by combining the contributions from characterization, homogeneity, and stability.