Direct Injection Analysis of Atenolol Enantionmers in Plasma Using an Achiral/Chiral Coupled Columun HPLC System

A novel HPLC system was developed with an achiral/chiral coupled column for the direct injection analysis of atenolol (AT) enantiomers in plasma. The system consists of a size-exclusion column, an ODS silica column and a newly developed β-cyclodextrin perhenylcarbamate(ph-β-CD)-bonses silica column connected in a series via two switching valves. The neat plasma sample was directly injected onto the size-exclusion column, and the deproteinzed fraction of AT enantiomers was concentrated on the ODS silica column. The enantimers were then transrerred and separated mutually on the ph-β-CD silica column. The calibration line for each of the AT enantiomers was linear in the range of plasma concentration of 10-200 ng/ml (r>0.9997) with good reproducibility (CV 97.4%) for both enatiomers. One analysis finished within 30 min. The developed system was applied to the enantioselective determination of plasma concentration-time curve of AT after the oral administration of racemic AT to a healthy volunteer.