Carolyn Acheson is a chemical engineer at the US EPA’s Office of Research and Development. She earned a Bachelor of Chemical Engineering from the University of Delaware and a Ph.D. from Cornell University. Dr. Acheson’s research has considered a variety of risk management technologies and chemicals including: polycyclic aromatic hydrocarbons; chlorinated solvents; alkyl phenol ethoxylates and their degradation products; and per- and poly-fluorinated alkyl substances (PFAS). Current research efforts include evaluating attenuation of chemicals when biosolids are land applied, and characterizing contaminated sites where PFAS products were used.
Use of ASTM 7968 to measure PFAS in soils at three sites
ASTM D7968 was used to measure Poly and perfluorinated Alkyl Substances (PFAS) concentrations in soils and sediments at three sites: Joint Base Elmendorf Richardson (JBER); DFSP Melville (DFSPM); and a research study evaluating land application. Concentrations and PFAS observed varied at the three sites. For example, PFOS ranged from 116 to 7.6 x 106 ng/kg at JBER, 30 to 340 ng/kg at DFSPM, and 6.2 x 103 to 2.7 x 104 at the research site. When using this method, a 2-g sample is placed in a polyethylene vial, spiked with isotopically labeled surrogates, and tumbled for 1 hr in a 50/50 methanol water mixture adjusted to pH 9-10 with ammonium hydroxide. The samples are centrifuged, and the extract is filtered. After adding acetic acid, the extract is analyzed by liquid chromatography with tandem mass spectrometry. The accuracy and precision of the method will be summarized based on data quality measurements.