Ultrashort PFAS in water

As the field of PFAS develops more substances and classes are being considered. Ultrashort PFAS are typically characterized as having one, two or three carbon atoms. Taking the two most common types of PFAS structures, perflouro-carboxylic and sulphonic acids (PFCA; PFSA) this means that there are five ultrashort compounds; trifluoroacetic acid (TFA), perfluoro-propionic acid (PFPrA), trifluoromethane sulhonic acid (TFMS; triflic acid), perfluoroethane sulphonic acid (PFEtS) and perfluoropropane sulphonic acid (PFPrS). These substances may not always be directly used as PFAS products, but rather occur as impurities, degradation products or manufactured for other purposes. Ultrashort PFAS are starting to receive more attention and a growing number of reports demonstrate their presence in the environment, especially in water.

Sources and occurrence in water

To date TFA has been most extensively studied. In precipitation, one source can be contamination in, and phototransformation of the refrigerants HFC-134a, HFO-1234yf and possibly other HFC/HCFC. TFA may also be formed from sources such as pharmaceuticals and pesticides (e.g. Fluazinam) having trifluoromethyl moieties, and at combustion of F-polymers (UBA, 2021; Miljødirektoratet, 2017). Moreover, TFA is employed as a reagent in different organic syntheses. TFMS is a “super acid” used in organic synthesis and can be included in lithium ion batteries. Concerning PFEtS and PFPrS they have been used for applications such as ion conductive agents, photolithography processing and can be present in AFFF (Björndotter, 2021). The five ultrashort compounds are all associated with high water solubility and low pKa values, which besides small molecular sizes, suggests that in the long-term the aquatic environment becomes the eventual sink.

The presence of ultrashort PFAS in drinking water has received more and more attention. In a study of 46 German drinking waters TFA was found at a median concentration of 900 ng/l, PFPrA 13 ng/l and TFMS 8 ng/l. Overall ultrashort PFAS typically comprised 98% of all PFAS detected (Neuwald et al., 2022). TFA levels in precipitation has been shown to increase over time e.g. 4-5 times since the mid-90’s in Germany and 17 times in Beijing (2002-12) (UBA, 2021; ATMOsphere, 2022). The current precipitation weighted average in Germany was found to be 335 ng/l (Freeling et al., 2020). Björnsdotter (2021) reported TFA and PFPrA concentrations in rain ranging from 18-300 and 0.9-4 ng/l, respectively, from the island of Visingsö (lake Vättern, SE). TFMS was occasionaly found at lower levels (<1 ng/l). Also in Denmark ultrashort PFAS has been assessed. In a study by the DK EPA (Miljøstyrelsen, 2021) TFA was found in nearly 90% of the groundwaters sampled (n=247) in concentrations up to 2400 ng/l. Regarding surface water ultrashort PFAS were found in three lakes in the vicinity of Stockholm in significant concentrations with TFA ranging from 400-2200 ng/l, PFPrA 5-1900 ng/l and TFMS <1-35 ng/l (Filipovic, unpubl).

Analysis of ultrashort PFAS

Eurofins now introduces a pack for ultrashort PFAS in water with a newly developed method. The pack (PLW98) contains all the five compounds mentioned above. The reporting limit (LOQ) varies from 1 ng/l (TFMS), 3 ng/l (PFPrA, PFEtS, PFPrS) to 50 ng/l (TFA). Two 100 ml PFAS bottles are required and delivery time is 5 working days. More details can found in our online search engine.

Contact Eurofins experts!

Questions about PFAS can be answered by our analytical advisory service, which can be reached via customer support, 010-490 8110 or e-mail: SpecialBUMiljo@eurofins.se

Ultrashort PFAS in water

Sources and occurrence in water

Analysis of ultrashort PFAS

Contact Eurofins experts!

Further Reading