Emily Parry, Limian Zhao, and Jennifer Hitchcock

Per and polyfluoroalkyl substances (PFAS) are a general class of anthropogenic compounds that possess high degree of fluorination. The carbon fluorine bond provides them valuable industrial properties and a resistance to degradation. These properties have also led to their ubiquitous presence in the environment. Human exposure and PFAS body burden have been linked with a variety health effects and research is ongoing. Epidemiological studies rely on quality analytical data complicated by the diversity of molecular structures in the PFAS class. A variety of methods to measure PFAS in biological samples have been reported such as protein precipitation (ppt), solid phase extraction (SPE), and ppt plus enhanced matrix removal (ppt+EMR). The current study presents an optimized sample preparation and liquid chromatography tandem mass spectrometry method (LC-MS/MS) for whole blood targeting 40 PFAS compounds. Sample volume and crashing solvent for protein precipitation was optimized for the higher abundance of proteins in whole blood and compared with protein precipitation plus EMR. EMR was shown to reduce matrix effects and still provide good compound recoveries. Injection volume and LC separation and instrument parameters were optimized to obtain low detection levels. Differences in sample preparation of serum and plasma will also be discussed. Focus of this work was targeted analysis, however, the sample preparation procedure would serve well for non-targeted analysis as EMR cleanup is not specific to any PFAS functional group (acids, ethers, etc.) allowing for the identification of new biologically relevant compounds.