A DOUBLE ISOTOPIC DERIVATIVE METHOD FOR THE QUANTITATIVE DETERMINATION OF OESTRONE AND 17β-OESTRADIOL IN PLASMA

Abstract

A method with a sensitivity of about 2 ng is evolved for the determination of oestrone and 17β-oestradiol in plasma. The method is based on the double isotopic derivative principle and makes use of the isotopes ³⁵S and ¹³¹I. The method includes: Extraction of plasma, purification of the extract, esterification of oestrone and 17β-oestradiol by means of p-iodobenzenesulphonyl chloride, purification of the esters formed by paper chromatography, counting of the radioactivities and calculation of the results. The procedures are described in detail and discussed. Determinations in plasma gave the following ranges of concentrations: Normally menstruating women, oestrone and 17β-oestradiol: 0.1–0.75 μg/l, some patients with primary or secondary amenorrhea, oestrone and 17β-oestradiol: 0–0.45 μg/l and pregnant women, oestrone: 1–10 μg/l and 17β-oestradiol: 2–30 μg/l.