Use of Micellar Mobile Phases and an HPLC Column Switching System for Direct Injection Determination of Urinary Free Cortisol

摘要

A direct injection method for the determination of urinary free Cortisol by an HPLC column switching system is presented. The first chromatographic column, which provides for sample preconcentration and clean-up, employs a micellar mobile phase. The second column, coupled on -line to the first, utilizes reversed-phase condition for analysis. UV detection is employed at 254 nm. Detection limit for urinary free Cortisol is 2.4 ng when 2 ml urine sample is injected. Nine samples were analyzed. The results were in a reasonable range. This method can be used successfully in the diagnosis of patients with hypercortisolism and Cushing's syndrome.