Total Fluorine Quantification Using PIGE at UMass Lowell*

Charged particles can be used to non-destructively probe for light elements in a sample. Typically referred to as Proton Induced Gamma-ray Emission (PIGE), a proton is used to excite a nucleus which promptly decays emitting characteristic gamma-rays, like mono-isotopic 19F. Per- and polyfluoroalkyl substances (PFAS) are a class of synthetic chemicals containing long F chains whose widespread presence in materials and industry has created an ongoing environmental hazard. Methods of detecting PFAS continue to be developed and improved, but they are expensive and lack efficiency. PIGE can be used to quickly screen samples, flagging those with a high fluorine content, a precursor to the presence of PFAS. 

 

The present work demonstrates the feasibility of screening for PFAS using the 5.5 MV Van de Graff accelerator at the UMass Lowell Radiation Laboratory, where a detection station for PIGE measurements has been implemented. A key component of the station is the High Purity Germanium (HPGe) detector. Essential to the present research project is an absolute efficiency calibration of the HPGe detector, which is needed to accurately determine the total fluorine content in a sample. Various samples containing known amounts of PFASs and other select makeup samples were tested using a 3.5 MeV proton beam. Data were collected using a digital acquisition system while analysis was performed with custom C++ code. This presentation will highlight the data analysis and preliminary results of total fluorine content from the various samples.