M. Bidart et G. Lesgards, DIRECT-INJECTION ANALYSIS OF 6-BETA-HYDROXYCORTISOL AND CORTISOL IN URINE BY HPLC-UV WITH ONLINE ISRP PRECOLUMN, Journal of liquid chromatography, 18(4), 1995, pp. 725-738
The simultaneous measurement of 6 beta-hydroxycortisol (6 beta-OHF) an
d cortisol (FF) is interesting for the evaluation of enzyme induction
in man. An on-line HPLC-UV analysis of urinary steroids is described.
In a first step, the biological sample was injected onto an ISRP (Inte
rnal Surface Reversed Phase) precolumn with water for the elimination
of proteins and indesirable products and for the concentration of hydr
ophobic molecules. In a second step, a simple gradient of acetonitrile
(ACN) in water, by a backflush procedure, eluted the retained analyte
s which are analysed by conventional RP-HPLC coupled with UV detection
.