The marine ecosystem is monitored through the analysis of some sentinel species, that is, fishes and
bivalves, also in consideration that seafood is reported as the primary dietary source of human exposure to PFAS.

In this frame, the utility of using different shellfish as indicator species in biomonitoring
studies has been investigated by analysing mussels, clams, oysters and scallops collected at the North-East coast of the Mediterranean Sea
and from Pacific and Atlantic Ocean. These filter-feeding organism has long been exploited for their ability to accumulate xenobiotics from the surrounding environment, thus to reflect the xenobiotics
presence of their proximity environment.

The different distribution of PFAS between water and sediments observed especially for
branched isomers and long-chain molecules highlighted in a number of studies in marine settings may also be reflected into biota.

In fact, in case of PFAS, both chemical structure and the characteristic of
the environment are considered to influence the degree ofaccumulation into an aquatic organism.

On this base, mussels, oysters, scallops and clams, which differently thrive in water or sediments, might reflect also a different spatial distribution of the PFAS presence in the same area.

To this aim, a method for the target and untargeted detection of PFAS in bivalves has been proposed by liquid chromatography coupled to accurate mass spectrometry (LC-QTOF).
The target analytes were enlisted in the EPA 533 regulation, which is currently applied for PFAS determination in drinking water and comprised legacy, emerging, branched and precursors of PFAS.

The untargeted analysis was carried out in accurate scan mode, and data were mined against an in-house database of 150 entries of PFAS substances.

Potential compounds with the highest detection frequency (DF) were then confirmed by reference material

Drug Test Anal. 2022;1–8.

DOI: 10.1002/dta.3282