DIRECT-INJECTION ASSAY OF DRUG ENANTIOMERS IN SERUM ON OVOMUCOID-BONDED SILICA MATERIALS BY LIQUID-CHROMATOGRAPHY

A high-performance liquid chromatographic (HPLC) method for the determ ination of drug enantiomers in serum was developed. The method involve s direct injection of serum samples on to an ovomucoid-bonded column, which is prepared by bonding of ovomucoid proteins to an aminopropyl-s ilica gel by the N,N'-disuccinimidyl carbonate activation method and s eparation of drug enantiomers on the column using a mixture of phospha te buffer and an organic solvent. High recoveries of serum proteins we re obtained using eluent pH values of 3, 4, 6 and 7 at phosphate buffe r concentrations above 50 mM, whereas the recovery was ca. 70% at an e luent pH of 5. The recovery of each enantiomer of basic and acidic dru gs from serum was almost 100%.