In the afternoon of June 13, invited by Professor Jiayin Dai and Associate Professor Yitao Pan, Associate Professor Leo Yeung and Anna Kärrman from Örebro University gave a wonderful academic report on the topic of "Comprehensive assessment of poly-/perfluoroalkyl substances (PFAS) in contaminated soil" and "Analysis of per- and polyfluoroalkyl substances (PFAS) related to paper products and manufacturing" for the faculty and students of Shanghai Jiao Tong University at the 182ed Environmental Forum.

To date, more than 5000 poly- and perfluoroalkyl substances (PFAS) have been registered on the global market. However, only a limited number of PFAS are being monitored in various monitoring programs. The production of "new" PFAS is usually not evaluated in current monitoring programs, which might lead to overlooking their existence in the environment and human exposure. Organofluorine mass balance analysis may be useful as a proxy to estimate overall exposure to PFAS. Leo Yeung introduced that when analyzing soil samples, the number of suspects was not missed if alkaline extraction was used; however, the amount of extractable organofluorine would be underestimated without acidic methanol extraction. Anna Kärrman provided an overview of methodologies and challenges regarding the analysis of PFAS by presenting two studies performed on paper products and sediment close to paper industries. Since possible target PFAS were numerous, and analytical standards were partly lacking, the methodologies also covered non-specific assessment, by analysis of fluorine, and oxidative pre-treatment.