Abstract
A method is presented for measuring cortisol and corticosterone in the same plasma sample by a single procedure. The steroids are extracted with chloroform, purified by paper chromatography, eluted and determined fluoro-metrically. A radioactive steroid tracer is carried through each determination and a correction for losses during the procedure is introduced based on isotope dilution measurements. The normal range of corticosterone in human beings is 0-5 [mu]g/100 ml. The normal range of cortisol is 4.0-17.7 [mu]g/ml. The ratio of cortisol/corticosterone was very variable between different subjects and in the same subject from day to day.