RAPID SCREENING OF OFLOXACIN ENANTIOMERS IN HUMAN URINE BY MOLECULARLY IMPRINTED SOLID-PHASE EXTRACTION COUPLED WITH LIGAND EXCHANGE CHROMATOGRAPHY

Abstract

A simple molecularly imprinted solid-phase extraction coupled with ligand exchange chromatography method was developed for rapid screening of R-(+)- and S-(−)-ofloxaxin in human urine. New molecularly imprinted microspheres (MIMs) were synthesized by aqueous suspension polymerization using pazufloxacin as pseudo template and it showed high affinity and selectivity to ofloxacin in aqueous solution. Baseline separation of ofloxacin enantiomers in human urine were obtained on a C₁₈ column in less than 20 min and no interferences from the protein or endogenous compounds were observed. Under the optimal conditions, good linearity of the method was obtained in the range of 0.07 to 60 µg/mL with the correlation coefficient of r² ≥ 0.9996 and the relative standard deviation of 2.9–4.5%. The detection limits signal-to-noise ratio of 3 (S/N = 3) was 0.03 µg/mL and 0.04 µg/mL for S-(−)- and R-(+)- ofloxaxin, respectively. The proposed method could be potential applied to investigate the stereoselectivity and pharmacokinetics of ofloxacin enantiomers in human body.

Keywords:

• enantioseparation
• human urine
• ligand exchange chromatography
• molecularly imprinted microspheres
• ofloxacin enantiomers
• pseudo-imprinted solid-phase extraction

Notes

S-OF: S-(−)-ofloxacin; R-OF: R-(+)-ofloxacin.