ZCATS

Zwitterionic, Cationic, Anionic, Total Surfactants

ZCATS™ is a state-of-the-art surface wipe test for a broad range of Per and Polyfluoroalkyl Substances (PFAS) on non-porous surfaces. Developed in collaboration with Dr. Ian Ross, ZCATS uses the best available technology to detect additional zwitterionic, cationic, and anionic PFAS on surfaces and containers which previously contained Aqueous Film-Forming Foam (AFFF).

Fluorinated-AFFF contains high levels of PFAS, some of which are highly persistent, mobile, bioaccumulative, and toxic.  AFFFs contain a mixture of legacy PFAS, such as PFOS, as well as precursor-PFAS which may breakdown to persistent PFOS and PFOA.  Precursor-PFAS are a chemically diverse mixture of zwitterionic, cationic, and anionic compounds (Backe, 2013), most of which cannot be analyzed by traditional targeted analyses like EPA Draft Method 1633.  This triple wipe method has been shown to effectively test for PFAS on impacted surfaces using time of flight elastic recoil detection (TOF-ERD).

ZCATS uses the best available technology to detect PFAS that may be present on surfaces. It covers a variety of PFAS using a triple wipe approach for collection, a sequential extraction (Nickerson, 2021), and the Total Oxidizable Precursor (TOP) Assay (Houtz, 2012) to breakdown precursor-PFAS into detectable analogues.

As the industry moves to lower and lower human health risk limits, the verification of decontamination procedures is essential. This test may help to understand the degree of the residual PFAS on surfaces.  As the industry moves to Fluorine Free Foam alternatives, any residual PFAS may either leach out over time or degrade into legacy PFAS, which could exceed limits.

_References

_{Backe WJ, Day TC, and Field JA. 2013. “Zwitterionic, cationic, and anionic fluorinated chemicals in aqueous film forming foam formulations and groundwater from U.S. military bases by nonaqueous large-volume injection HPLC-MS/ MS.” Environmental Science and Technology. 47(10): 5226-5234}

_{Nickerson A, et al. 2020. “Enhanced Extraction of AFFF-Associated PFASs from Source Zone Soils.” Environmental Science & Technology. 54 (8), 4952-4962.}

_{Houtz EF and Sedlak DL. 2012. “Oxidative Conversion as a Means of Detecting Precursors to Perfluoroalkyl Acids in Urban Runoff.” Environmental Science & Technology 46 (17), 9342-9349}