Urinary elimination of urinary tetrahydroaldosterone measured by gas-phase chromatography. Normal values in adults

The authors describe a method of titration of tetrahydroaldosterone in the urine, requiring an internal non-radioactive standard. This method uses high performance liquid chromatography as a mean of isolating tetrahydroaldosterone (THAldo) and chromatography in gaseous phase as a method of titration in the form of heptafluorobutyrate after oxidation into gamma lactone. It permits to detect 3 ng of gamma lactone of THAldo corresponding to a urinary concentration of 16 nmol/l.