Hplc grade glass distilled solvents

Testosterone, androstenedione, DHT, DHA, epiTestosterone (EpiT), dehydroepiandrosterone (DHEA), formic acid (FA) ≥98%, hydrazine monohydrate, dichloromethane (DCM), trifluoroacetic acid (TFA), ammonium acetate and 2-fluoro-1-methylpyridinium-p-toluenesulfonate (FMP-TS) were from Sigma-Aldrich, (Dorset, UK). 2,3,4-¹³C_3-Testosterone (¹³C₃-T), 99%, 2,3,4-¹³C₃-androstenedione (¹³C₃-A4), ≥98%, 2,3,4-¹³C₃-5α-dihydroTestosterone (¹³C₃-DHT), ≥97% were from IsoSciences (Philadelphia, USA). Certified solutions of Testosterone, androstendione (both 1 mg/mL in acetonitrile) and DHT (1 mg/mL in methanol) and ¹³C₃-T and ¹³C₃-A4 (100 µg/mL in acetonitrile) were from Cerilliant (Texas, USA). HPLC grade glass distilled solvents (methanol, acetonitrile, acetone, n-hexane, DCM and water) and LC-MS grade solvents (methanol, acetonitrile and water) were from Fisher Scientific UK Limited (Leicestershire, UK).

Estrone (E1), 17β-estradiol (E2), 17α-estradiol (17αE2), formic acid (FA; ≥98%), triethylamine (TEA; ≥99.5%) and 2-fluoro-1-methylpyridinium-p-toluenesulfonate (FMP-TS) were from Sigma-Aldrich, Inc. (St. Louis, USA). 3,4-[¹³C]₂-estrone (¹³C₂E1), 2,4,16,16-[²H]₄-estrone (95-97%) (d₄E1), 3,4-[¹³C]₂-estradiol (¹³C₂E2) and 2,4,16,16-[²H]₄-estradiol (d₄E2) were from Cambridge Isotope laboratories Inc. (Andover, USA). HPLC grade glass distilled solvents (methanol, acetone, hexane and water) were from Fisher Scientific UK Limited (Leicestershire, UK).