Pesticide grade hexane

HPLC-grade methanol (MeOH), tris(dibenzylideneacetone)dipalladium(0) and 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl were purchased from Sigma-Aldrich (Milwaukee, WI, US). 2,3-Dichlorobenzeneboronic acid was obtained from Combi-blocks (San Diego, CA, US). 2,3,6-Trichloroiodobenzene was provided by Oakwood Products, Inc (Estill, SC, US). All solvents used for synthesis were purchased from Thermo Fisher Scientific (Waltham, MA, US). Pesticide grade hexane was obtained from Fisher Scientific (Pittsburg, PA, US). De-ionized, ultra-filtered water for the HPLC separations was obtained using a Milli-Q Academic A10 system (Millipore, Billerica, Massachusetts, US).

PCB-126 and PCB-11 were from Ultra Scientific (North Kingstown, RI), beta-naphthoflavone (BNF) from Fisher Scientific (Pittsburg, PA), and 7-ethoxyresorufin-O-deethylase (7-ER) from MP Biomedicals (Solon, OH). All chemicals were dissolved in 100% dimethyl sulfoxide (DMSO) from Fisher Scientific (Fair Lawn, NJ). Stock solutions were stored at −20°C in glass amber vials, and were fully thawed and vortexed before use. For zebrafish concentration analyses, PCB-13 was used as a surrogate standard (SS) from AccuStandard (New Haven, CT), d5-PCB-30 was used as an internal standard (IS) from Cambridge Isotope Laboratories (Andover, MA), and pesticide-grade hexane was used from Fisher Chemical (Beerse, Belgium).