Occurrence and prevalence of per- and polyfluoroalkyl substances in the sediment pore water of mariculture sites: Novel findings of PFASs from the Bohai and Yellow Seas using a newly established analytical method

A new method for the determination of 26 legacy and emerging per- and polyfluoroalkyl substances (PFASs) in marine sediment pore water was developed using online solid phase extraction coupled with liquid chromatography-tandem mass spectrometry. The proposed method requires only about 1 mL of pore water samples. Satisfactory recoveries of most target PFASs (83.55–125.30 %) were achieved, with good precision (RSD of 1.09–16.53 %), linearity (R2 ≥ 0.990), and sensitivity (MDLs: 0.05 ng/L–5.00 ng/L for most PFASs). Subsequently, the method was applied to determine PFASs in the sediment pore water of five mariculture bays in the Bohai and Yellow Seas of China for the first time. Fifteen PFASs were detected with total concentrations ranging from 150.23 ng/L to 1838.48 ng/L (mean = 636.80 ng/L). The ∑PFASs and PFOA concentrations in sediment pore water were remarkably higher than those in surface seawater (tens of ng/L), indicating that the potential toxic effect of PFASs on benthic organisms may be underestimated. PFPeA was mainly distributed in pore water, and the partition of PFHpA (50.99 %) and PFOA (49.01 %) was almost equal in the solid and liquid phases. The proportions of all other PFASs partitioned in marine sediments were significantly higher than those in pore water. [Display omitted] •A convenient method for the detection of PFASs in marine sediment pore water was developed.•Only about 1 mL of actual sediment pore water is needed to determine various PFASs.•High levels of PFASs were detected in pore water from five mariculture bays of China.•Different PFASs exhibit varying partitioning behaviors at the sediment–pore water interface.•Great attention should be paid to PFASs in the sediment pore water of mariculture areas.