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.