Studies of microhigh-performance liquid chromatography. IV. Application of the micro pre-column method to the analysis of corticosteroids in serum.

The micro pre-column method, which is a useful method for the pre-treatment of samples, was applied to the analysis of corticosteroids in serum. Corticosteroids were concentrated in a micro pre-column packed with porous styrene-divinylbenzene copolymer particles and separated in a micro separation column packed with porous silica particles. Concentrations of corticosterone, cortisone and cortisol in the 20-130 ppb range were determined individually by pre-treatment of only 0.2 ml of serum.