Solid-phase extraction on Styrosorb cartridges as a sample pretreatment method in the stereoselective analysis of propranolol in human serum.

Sample pretreatment using solid-phase extraction (SPE) on cartridges filled with small-particle Styrosorb porous polystyrene-based sorbent has been used in the analysis of propranolol enantiomers in human serum by high-performance liquid chromatography (HPLC) with fluorescent detection. SPE on Sep-Pak C18 cartridges was used as a reference pretreatment method. The propranolol content of the samples was determined by achiral normal-phase HPLC and the enantiomeric ratio of propranolol (S/R) was then determined by chiral HPLC on a column with silica-bonded cellulose-tris(3,5-dimethylphenyl carbamate). Recoveries of propranolol from serum using SPE on Styrosorb and C18 phases were 97 +/- 5% and 96 +/- 5%, respectively. Detection and quantification limits for propranolol enantiomers were 4 and 7 ng/ml, respectively.