Comparison of a simplified radioimmunoassay with a gas-liquid chromatographic method for urinary aldosterone

A simplified radioimmunoassay for the measurement of aldosterone in urine, requiring only an extraction without any further purification is described. The results obtained on 47 urine specimens were compared with those obtained by a gas-liquid chromatographic method. An excellent correlation was found (r = 0.932) and values obtained by both methods were similar so that this RIA has been satisfactorily adopted in our laboratory for one year. Some discrepancies, however, led us to consider the problem of preservation and storage of biological fluids.