A serial PFASs sorption technique coupled with adapted high volume direct aqueous injection LCMS method

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous global environmental contaminants, environmentally persistent, mobile, can bioaccumulate and are toxic. Increasing emphasis is placed on the immobilisation and removal of PFAS from contaminated environmental matrices such as: potable water, surface water, groundwater, wastewater, sediments and soils (Dauchy et al., 2017; Cao et al., 2019; Hepburn et al., 2019). To achieve this, development of PFAS sorbents is increasingly undertaken (Du et al., 2014). Sorption studies are used to observe the interaction of sorbent and sorbate, but have two key limitations when undertaking sorption experiments for PFAS (1) the experimental protocol and (2) analytical techniques. The current batch sorption methods approached recommended by OECD Guideline 106 (OECD, 2000) are problematic, firstly, due to large sample numbers and PFAS specific laboratory difficulties, including near ubiquitous background PFAS contamination. Secondly, PFAS analytical techniques currently require solid-phase extraction (SPE) to be employed, which is slow and expensive, prior to instrumental analysis with liquid chromatography-mass spectrometry (LC-MS). A suitable alternative approach is needed to mitigate the drawbacks of current methodologies whilst catering for the high sample throughput required by benchtop trials characterising the sorption behaviour of PFAS - sorbent pairings. • A suitable method for PFAS measurement, overcoming shortcomings of current batch sorption methodologies is presented; • The method can be applied to a wide range of sorbents and sorption environment conditions associated with PFAS immobilisation or removal in the environment; • The presented method is novel through its high sample throughput, simple approach and minimisation of cross contamination sources.