17β estradiol 2 4 16 16 17 d5

All extraction and derivatization solvents were chromatography grade from EMD Chemicals (Billerica, MA). Monodeuterated ethanol was obtained from Acros Organics (New Jersey), and heptafluorobutyric acid anhydride was obtained from Fluka (Sigma-Aldrich, St. Louis, MO). Pregnenolone, pregnanolone, 3α,5β-THDOC, and 3α,5β-androstanediol were procured from Steraloids (Newport, RI), and all other native steroid standards were synthesized by Dr. Robert Purdy (Scripps Research Institute, La Jolla, CA). The internal standard (ISTD) that was used in all assays was 17β-estradiol-2,4,16,16,17-d5 (CDN Isotopes, Pointe-Claire, Quebec, Canada). Stripped human serum (SHS) was purchased from Gemini Bioproducts (West Sacramento, CA).

All extraction and derivatization solvents were chromatography grade (EMD Chemicals, Billerica, MA). Monodeuterated ethanol was obtained from Acros Organics (New Jersey), the derivatizing reagent heptafluorobutyric acid anhydride (HFAA) was obtained from Fluka (Sigma-Aldrich, St. Louis, MO), and the neurosteroids pregnenolone, pregnanolone, 3α,5β-THDOC, and 3α,5β-androstanediol were obtained from Steraloids (Newport, RI). All other native neurosteroid standards were synthesized by the late Dr. Robert Purdy. Similar to Snelling et al. (2014) (link), the internal standard (ISTD) was 17β-estradiol-2,4,16,16,17-d5 (CDN Isotopes, Pointe-Claire, Quebec, Canada). Ultra-pure water (double distilled; ddH₂O) from a MilliQ system (Millipore Corporation, Bedford, MA) was used. Activated powdered charcoal (Darco-G-60) and Dextran (T-70) were obtained from Sigma-Aldrich.