PFAs

Scientists now have begun to work hard to identify, extract and quantify per- and polyfluorinated alkyl substances (PFASs), specifically perfluoroalkane sulfonic acids (PFSAs), perfluoroalkyl carboxylic acids (PFCAs) and associated compounds, such as, polyfluoroalkyl phosphoric acid diesters (diPAPs), perfluoroalkyl phosphinic acids (PFPiAs) and perfluoroalkyl phosphonic acids (PFPAs).

PFAs in Sediment

An international group of Chinese, Canadian, and American scientists report in the December issue of Chemosphere a new method, liquid chromatography coupled to mass spectrometry (LC-MS/MS), to quantify these compounds in sediment cores.

Below is a map showing the study locations in the Great Lakes area.

Chemosphere Volume 164, December 2016, Pages 535–546

Greatest Concentrations Found in Lake Ontario

They found the greatest average concentrations of PFASs in Lake Ontario sediment to be 13.1 parts per trillion. The compound perfluorooctane sulfonic acid (PFOS) constituted over 80% of the total mass.

The concentrations in Lake Ontario are 100 times greater than in remote lakes where the only source of PFAs comes only from atmospheric deposition and not from also rivers. Riverine sources appear to consist mostly of by PFOS and not PFAS.

These results provide scientists with a potential forensic way to differentiate where polyfluorinated contaminants come from.