Chemicals
HPLC grade methanol, acetonitrile, 99.998% trace metals basis lithium chloride, analytical-reagent-grade acetate acid, L-Ascorbic acid, β-glucuronidase-arylsulfatase from Helix pomatia, sodium bicarbonate, corticosterone, cortisol, cortisone, dehydroepiandrosterone, dehydrotestosterone , 11-deoxycorticosterone, 11-deoxycortisol, estriol, 17α-hydroxypregnenolone, 17α-hydroxyprogesterone, pregnenolone, progesterone, testosterone, androstene-3,17-dione-2,3,4-13C3, corticosterone-9,11,11,12-d4, cortisol-9,11,12,12-d4, cortisone-2,3,4-13C3, dehydroepiandrosterone-2,2,3,4,4-d5, estrone-2,3,4-13C3, 17α-hydroxypregnenolone-21,21,21-d3, 17α-hydroxyprogesterone-2,3,4-13C3, pregnenolone-20,21-13C2-16,16-d2solution, progesterone-2,3,4-13C3 and testosterone-2,3,4-13C3 were purchased from Sigma-Aldrich (Tokyo, Japan). Alphadolone , allopregnenolone , tetrahydrocortisol, tetrahydrocortisone, 11-β-hydroxyandrosterone, tetrahydrocorticosterone, tetrahydrodeoxycorticosterone, tetrahydrodeoxycortisol, 16-hydroxyestrone, 16-hydroxyestrone-2,3,4-13C3, estriol-d3 and tetrahydrocortisone-d6were supplied by Toronto Research Chemicals (North York, Canada). Adrenosterone, androsterone, androstenedione, estrone, and estradiol was purchased from Tokyo Chemical Industry (Tokyo, Japan). 7α-hydroxydehydroepiandrosterone and 7α-hydroxypregnenolone were supplied by Nacalai tesque (Kyoto, Japan). HPLC grade formic acid was obtained from FUJIFILM Wako Pure Chemical Co. (Osaka, Japan). Ultrapure water was prepared using a Organo puric ω (Tokyo, Japan). The HF Bond Elute C18 (1 mL, 50 mg) was purchased from Agilent Technologies, Inc. (Santa Clara, CA). Creatinine (urinary) Colorimetric Assay kit was purchased from Cayman Chemical (Ann Arbor, MI). The amount of creatinine (mg) was measured according to the manufacturer’s manual.