Characterizing the long-term occurrence and anthropogenic drivers of per- and polyfluoroalkyl substances in surface water of the Rhine River

Spatial and Seasonal Distribution, Source Apportionment, and Risk Assessment of Dissolved-Phase Ultraviolet Absorbents and Synthetic Phenolic and Amino Antioxidants in the Pearl River Delta (PRD), China

“…The positive matrix factorization (PMF) receptor model was used to decompose a specified sample data matrix into factor contributions and factor profiles to determine the factors or sources affecting the specified data set . To date, PMF has been applied for identifying potential sources of xenobiotics in aquatic environments. , Regarding the significance of estimated uncertainty for each data value in PMF analysis, the uncertainty was estimated currently based on the LOQ and error value (set to 0.2) of the individual AOs . The uncertainties were calculated with eq or if the measured AO concentration was lower or higher than the LOQ, respectively: uncertainty = 5 × LOQ 6 uncertainty = false( 0.2 × concentration AOs ) 2 + LOQ 2 …”

“…36 To date, PMF has been applied for identifying potential sources of xenobiotics in aquatic environments. 37,38 Regarding the significance of estimated uncertainty for each data value in PMF analysis, the uncertainty was estimated currently based on the LOQ and error value (set to 0.2) of the individual AOs. 39 The uncertainties were calculated with eq 1 or 2 if the measured AO concentration was lower or higher than the LOQ, respectively:…”