The determination of two emerging perfluoroalkyl substances and related halogenated sulfonic acids and their significance for the drinking water supply chain D Vughs 1 , KA Baken 1,1 , MML Dingemans 1 , P de Voogt 1,2,* 1 KWR Watercycle Research Institute, Groningenhaven 7, 3430 BB Nieuwegein, The Netherlands 2 IBED-FAME, University of Amsterdam, Science Park 904, Amsterdam, The Netherlands *Corresponding author, pim.de.voogt@kwrwater.nl Supplementary information Table of contents  Table SI-1. Technical names, structures, CAS numbers and full molecular names of emerging fluorinated compounds used in this study Materials and Methods  Table SI-2. Sample description sampling campaign  Analytical method for FOSA Quality assurance  Table SI-3. Stability study results for F 3 -MSA and HFPO-DA in drinking and surface water after 21 days (N=7)  Table SI-4. Validation results of F3-MSA in drinking- and surface water (n=8)  Table S-5 Validation results of HFPO-Da in drinking- and surface water (n=8) Results  Table SI-6. Results sampling campaign: concentrations of F3-MSA AND HFPO-DA  Table SI-7 Halogenated MSAs selected for suspect screening  Table SI-8 Results suspect screening of Cl-MSA, Cl 2 -MSA, Cl 3 -MSA, Br-MSA, Br 2 -MSA and BrCl-MSA  Figure SI-1: concentrations of HFPO-DA detected in raw water and the corresponding drinking water from several locations. Toxicological evaluation  Table SI-9 Structural alerts and Cramer classification indicated by OECD QSAR Toolbox (V3.4.0.17) profiling 1 Current address: VITO N.V., Boeretang 200,2400 Mol, Belgium Electronic Supplementary Material (ESI) for Environmental Science: Processes & Impacts. This journal is © The Royal Society of Chemistry 2019