在线固相萃取大体积进样-高效液相色谱-串联质谱法测定水中23种全氟化合物OA

This study established a novel method for the simultaneous determination of 23 perfluoro-alkyl substances(PFASs)in surface water,groundwater,seawater,domestic sewage,and industri-al wastewater by combining online solid-phase extraction with large-volume injection technology and high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS).Water samples were prepared for analysis by mixing them with methanol and ammonium acetate(final concentrations:10%methanol and 2 mmol/L ammonium acetate),after which they were filtered and directly inject-ed.Following online enrichment on a WAX column,the analytes were transferred to a C18 analytical column and separated within 14 min by gradient elution using acetonitrile-2 mmol/L ammonium ace-tate as the mobile phase.The PFASs were detected by tandem mass spectrometry in multiple reaction monitoring(MRM)mode and were quantified using the isotope internal standard method.The 23 tar-get PFASs exhibited good linearity in the range of 0.50-100 ng/L,with all correlation coefficients(r)exceeding 0.998,and detection limits ranging from 0.05 to 0.42 ng/L.The spiked recoveries of 23 target PFASs were 78%-118%,with relative standard deviations of 2.5%-15%.The developed meth-od was used to analyze 14 real water samples collected in Liaoning Province,including surface water,groundwater,seawater,and the effluent of a wastewater treatment plant.Eleven PFASs were detect-ed,with PFBA,PFPeA,PFHxA,PFOA,PFBS,and PFOS being the predominant contami-nants.Compared with conventional offline solid-phase extraction methods,this method requires small water samples(only 5 mL)and features a high degree of automation in terms of sample pretreat-ment.This green analytical technique has several advantageous features:low sample consumption,low solvent usage,broad detectable target spectrum,high analytical efficiency,and excellent envi-ronmental compatibility.The new method provides a simple,rapid,and accurate analytical tool for routinely monitoring legacy and emerging PFASs in different types of water environments.