Determination of oestradiol-17 beta in human serum by isotope dilution-mass spectrometry. Definitive methods in clinical chemistry, II.
A definitive method is described for the measurement of oestradiol-17 beta in human serum. The method is based on the principle of isotope dilution-mass spectrometry. The analytical procedure consists of the following steps: addition of [4-14 C]oestradiol-17 beta to the plasma sample; extraction of the 14C-labelled and the non-labelled oestradiol-17 beta with dichloromethane; purification of the oestradiol-17 beta fraction by column chromatography on Sephadex LH-20; formation of the 3,17 beta-diheptafluorobutyric ester of oestradiol-17 beta; selected ion monitoring at m/z-values 664 and 666 by gas liquid chromatography-mass spectrometry. The accuracy of the method is based on the high specificity of mass spectrometry and on the exact control of recovery employing the principle of isotope dilution. Coefficients of variation from day to day varied between 1.0% and 2.5% in the range of 0.319 to 3.53 nmol/l. The lower limit of detection (ratio of signal to noise 3:1) is 5 pg oestradiol-17 beta per sample.
D004958:Estradiol / Q000097:blood*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D011865:Radioisotope Dilution Technique
D004958:Estradiol