Estimation of Estradiol-17β by Gas-Liquid Chromatography with Electron Capture Detection

Abstract

Over the past three years our laboratory has been interested in steroid biosynthesis in vivo by the canine ovary (1–4). Information on pathways of steroid biotransformation in this organ has been obtained by infusing labeled steroids via the ovarian artery and determining radioactive steroids in venous blood of the infused organ. Much knowledge could be gained from such experiments if the specific activity of the radioactive metabolites could be determined rather than only the amounts of isotope accumulated in isolated compounds (5). Methods are available for the estimation of small amounts of steroids in blood and urine. Most micro techniques, however, use isotopes of different energy spectra — one isotope being used for correcting losses of steroids occurring during processing of the sample, the other one serving as a reagent to quantitate the steroid to be measured (6). Such techniques cannot be applied to the estimation of steroids in biological specimens already containing these isotopes (7).

This work was in part supported by training grant #T4-CA 500 and grant #AM 06651-03 from the U.S. Public Health Service, Bethesda, Md.