Studies on Assay Conditions of Semm Cortisol Using High Pressure Liquid Chromatography

Abstract

Assay method of serum cortisol using high pressure liquid chromatography was established and the various assay conditions were studied. The hormone was extracted from 1.0ml of sera obtained from healthy students and hospital patients. The final extracts were applied to Zorbax Sil column in Shimazu-Du Pont 830. Cortisol fraction separated from the internal standard (prednisolone) and other fractions was estimated as the area (height×Width). Normal Value Was 10.7±3.0μg/dl (Mean±S. D.) Obtained from 15 healthy males and 3 healthy females. The recovery of internal standard (prednisolone) was an important index for the judgment of accompanying technical errors. The recovery should be over 50%, over which the assay error was within ±5 to 10%. The present method for serum cortisol assay was particularly useful in clinical medicine to test the adenohypophysis-adrenocortical hormone system, for instance in feedback inhibition test on ACTH secretion and ACTH load test on glucocorticoid secretion.