Determination of urinary 18-hydroxycortisol by isocratic normal-phase high-performance liquid chromatography.

Abstract

A method for the determination of urinary 18-hydroxycortisol by high-performance liquid chromatography is described. Urinary samples were first mixed with an internal standard, 18-hydroxyprednisolone. 18-Hydroxycortisol and 18-hydroxyprednisolone, extracted by a Bond Elut column, were dehydrated by 1% (w/v) p-toluenesulphonic acid to the 11,18-epoxides. The epoxides were separated into two distinct peaks on a Resolve Silica column with a mobile phase of chloroform-methanol (100:2.5, v/v). The detection wavelength was 248 nm. The urinary 18-hydroxycortisol concentration was calculated from peak-height ratio of 11,18-epoxycortisol to 11,18-epoxyprednisolone. The linearity of the ratio was satisfactory in the range 12.5-300 ng per injection of 11,18-epoxycortisol. A specific increase of urinary 18-hydroxycortisol in patients with primary aldosteronism was demonstrated.

• Authors: H Chiba, Y Ito, K Matsuno, K Kobayashi, T Kurosawa, S Ikegawa, R Mahara, M Tohma
• Journal: Journal of chromatography (J Chromatogr) Vol. 613 Issue 1 Pg. 132-6 (Mar 05 1993) Netherlands
• PMID: 8458890 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• 18-hydroxycortisol
• Hydrocortisone

Topics

• Chromatography, High Pressure Liquid (methods)
• Humans
• Hydrocortisone (analogs & derivatives, urine)
• Hyperaldosteronism (urine)
• Reproducibility of Results