Supercritical fluid extraction of steroids from biological samples and first experience with solid-phase microextraction–liquid chromatography

Modern extraction techniques, supercritical fluid extraction (SFE) and solid-phase microextraction (SPME) were used for isolation of four corticosteroids from biological matrices. SFE was applied for extraction from solid matrices — hydromatrix and pig muscle. The effects of various extraction conditions were studied. Good recoveries of corticosteroids from hydromatrix were obtained under moderate extraction conditions and without modification of carbon dioxide. On the contrary, the best recoveries from spiked pig muscle were obtained with modified carbon dioxide. SPME was used for extraction from liquid samples — water and urine. The eventuality of the use of this fast solvent-free technique in steroid analysis is demonstrated. Several extraction conditions were optimized. Extracted steroids were analyzed by HPLC–UV and a special SPME–HPLC interface was used for combination with SPME.