ALS Product catalogues SOIL, SLUDGE and SEDIMENT | Page 26
PERFLUORINATED
COMPOUNDS (PFC)
As a result of the growth of the synthetic chemical industry over the
last 50 years, many thousands of new fluorinated molecules have been
synthesised and through various mechanisms, have become almost
ubiquitous in the environment. A multitude of poly- and perfluoroalkyl
substances (PFAS), valued for their ability to repel both water and oils,
have been used for decades for diverse applications such as water
repellent “outdoor” fabrics, stain resistant carpets, non-stick frying
pans and firefighting foams.
PFOS (perfluorooctane sulphonate) and PFOA (perfluorooctanoate) are the best known
examples of PFAS. Their potential impact on human health has already been recognized
internationally as they are extremely persistent, bioaccumulative and toxic.
As a result, PFOS is restricted under the Stockholm Convention and classed as a persistent
organic pollutant (POP), with PFOA being actively considered for inclusion.
PFOS is also listed in the European Union Priority Substances Directive (2013/39/EU) with
Environmental Quality Standards (EQSs) in fresh, surface water, coastal waters and biota.
However, more recently, regulators’ in differing countries interest and concern has
expanded to take in a much wider number of the PFAS now known to be present in
the environment such as perfluorinated or polyfluorinated alkyl substances compounds
(PFAS) which have entered the environment from aqueous film forming foam (AFFF) and
multiple other products. Perfluorinated compounds do not break down or biotransform
under natural conditions in the environment. Whereas, the polyfluorinated compounds
are sometimes termed “precursors” as they can biotransform to form more simple
Perfluorinated alkyl acids such as PFOA.
As a result, there are significant analytical challenges to overcome when considering how
to assess soil and groundwater contaminated with PFAS as there are multiple analytes
to consider, not just PFOS and PFOA, with many of the perfluorinated compounds being
of unknown composition.
Routine analysis of these compounds is undertaken by Liquid Chromatography - Triple
Quadrupole Mass Spectrometry (LC-QQQ). This analytical technique is very selective and
sens