EVALUATION OF AN OESTRADIOL RADIOIMMUNOASSAY BY HIGH-RESOLUTION MASS FRAGMENTOGRAPHY

Abstract

A technique for the analysis and measurement of C19-steroids by high-resolution selected ion monitoring previously was used to study the level of endogenous steroids in human prostatic tissue. A similar procedure has now been used as a reference method to determine the concentration of estradiol-17.beta. in plasma samples from a quality control scheme for the Supra-Regional Assay Service (SAS) in the UK. Results from the combined gas chromatographic-mass spectrometric (GS-MS) method were compared with those obtained from the assay of estradiol-17.beta. with the routine radioimmunoassay procedure previously used in this laboratory. Despite the close agreement between the 2 methods, the use of mass fragmentography with steroids labeled with stable isotopes will be of considerable value in providing definitive methodology to check steroid concentrations in quality control of samples of plasma and thereby a more effective quality control scheme.