Field Deployable PFCs Sensors for Contaminated Soil Screening

Perfluorooctanesulfonic acid (PFOS) is an anionic surfactant species that is a member of a large family of ubiquitous and emerging environmental contaminants known as perfluoro chemicals (PFCs). Soil and groundwater contamination by PFCs have been caused by legal emissions from industrial manufacturers (carpets, lubricants, paints, packaging, cookware), protectant spray consumer products, polymer producers, fire fighting foams, and chromium plating facilities. Preliminary assessment of contaminated sites are underway but are extremely costly and time consuming. This is due in part to the complicated requirements for analysis of PFC contaminated samples. Proper analysis requires expensive and highly specialized laboratory equipment and personnel (Ph.D. level) for effective sampling, sample preservation, sample preparation and analytical methods. Off-line and off-site LC/MS/MS analytical methods have been shown to have the selectivity and low limits of detection required for PFOS measurement (EPA Method 537). However, the total analysis price/sample is costly and is driven in part by time consuming (30-60 days) sample preparation in a wide variety of matrices with co­-contaminants (i.e., NAPL). Furthermore, long term monitoring costs become intolerable under these parameters. Recent work has shown that ion selective sensors fabricated from fluorous materials can be used to measure PFOS in drinking and ground water down to the ppt level with no sample preparation. However, PFCs become trapped in the compact soils above aquifers and can slowly elute into groundwater over time. PFCs are also likely transported away from the source via rivers, creeks or stormwater routes. All major sources of PFCs and transport pathways are typically identified to properlyremediate. However, current analysis methods are not amenable to wide spatial and temporal sampling. Furthermore,most of the site assessment work at known PFC contaminated sites has sorely focused on PFC levels in groundwater. The goal of this proposal is to demonstrate the effectiveness of a hand held PFOS ion-selective electrode (ISE) device that can screen for the presence of PFCs in soils and enable high spatial resolution to testing. This work will complement ongoing research on a PFC sensor for prescreening PFCs in water.