TY - JOUR
AU1 - Schöneshöfer,, M
AU2 - Kage,, A
AU3 - Weber,, B
AU4 - Lenz,, I
AU5 - Köttgen,, E
AB - Abstract This is a fully automated method for the specific assessment of urinary free cortisol. A 1-mL urine sample is concentrated and prepurified on a reversed-phase precolumn with alkaline, acid, and organic washes. After selective elution, the cortisol-containing organic eluate is "polarized" by admixing water in such a way that cortisol is focused on the top of a second reversed-phase precolumn. From this precolumn, cortisol is desorbed by backflush, separated from the still-remaining related compounds on an analytical column, and finally detected by ultraviolet absorbance. Losses of cortisol throughout the total procedure are negligible and thus external calibration is feasible for quantification. CVs were 4.1% for interassay variability, 2.6% for intra-assay variability. Cortisol concentrations down to 15 nmol/L are assayable, we estimated the median amount of free cortisol excreted daily by normal students, outpatients, hospitalized patients, and patients under intensive care. After stimulation with corticotropin1-24, the median concentration of free cortisol in urine increased from 99 nmol/L to 1238 nmol/L (n = 6). Results by radioimmunoassay for normal persons and hospitalized patients were about fourfold those by this technique. The same method can also be used for free cortisone in urine. This content is only available as a PDF. © 1985 The American Association for Clinical Chemistry, Inc. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)
TI - Determination of urinary free cortisol by on-line liquid chromatography.
JF - Clinical Chemistry
DO - 10.1093/clinchem/31.4.564
DA - 1985-04-01
UR - https://www.deepdyve.com/lp/oxford-university-press/determination-of-urinary-free-cortisol-by-on-line-liquid-0tlV044tbz
SP - 564
EP - 568
VL - 31
IS - 4
DP - DeepDyve
ER -