Page S-1/5 Supporting Information Measurement of Selected Polybrominated Diphenyl ethers, Polybrominated and Polychlorinated Biphenyls, and Organochlorine Pesticides in Human Serum and Milk using Comprehensive Two-Dimensional Gas Chromatography Isotope Dilution Time-of-Flight Mass Spectrometry Jean-François Focant*, Andreas Sjödin, Wayman E. Turner, and Donald G. Patterson Jr. Organic Analytical Toxicology (OAT), Division of Laboratory Sciences (DLS), National Center for Environmental Health (NCEH), Centers for Disease Control and prevention (CDC), 4770 Buford Hwy NE Mail Stop F-17, Atlanta, GA, 30341 *Corresponding Author current address: Mass Spectrometry Laboratory, University of Liège Allée de la Chimie, B6c, B-4000 Liège, Belgium Phone: +32 4 366 35 31 Fax: +32 4 366 43 87 E-mail: JF.Focant@ulg.ac.be