Despite efforts to develop robust analytical methods for the determination of perfluorinated compounds (PFCs) such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in surface water, little has been published on the importance of sample collection, storage, and preservation procedures. In this study, an existing method was improved for use in a large scale cross sectional study of the Upper Mississippi River Basin, one of the largest watersheds in the world. Samples were collected in 2008 in an effort that involved multiple sample sites and collection teams, long range transportation, and storage of up to 4 weeks before analysis. At least one out of 13 target compounds was found above the LOQ in 94% of the 177 samples, with 80% of all of the individual measurements being below 10 ng/L. The most abundant PFCs were perfluorobutanoic acid (C4; 77% > LOQ), perfluorooctanoic acid (C8; 73%), perfluorooctane sulfonate (PFOS; 71%), perfluorohexanoic acid (C6; 70%), and perfluoroheptanoic acid (C7; 69%), with the remaining target compounds occurring above the LOQ in less than 50% of the samples. The highest concentrations recorded include C4 at 458 ng/L, PFOS at 245 ng/L, and C8 at 125 ng/L, suggesting various point source inputs at some specific sampling locations.
Citation: Environmental Science & Technology
Pub Type: Journals
Perfluorinated Compounds (PFCs), Perfluorobutanoic acid (PFBA), Perfluorooctanoic acid (PFOA), Perfluorobutane sulfonate (PFBS), Perfluorooctane sulfonate (PFOS), Upper Mississippi River