Determining Cortisol and Cortisone Simultaneously in Salmonid Plasma by Competitive Protein Binding

A method was developed for the simultaneous determination of nanogram quantities of cortisol and cortisone in 0.1-ml samples of salmonid plasma by competitive protein binding (CPB). The steroids were separated by thin-layer chromatography on silica gel and CPB analysis was performed with chicken serum in the presence of Florisil.