Validation and Application of Molecularly Imprinted Polymers for SPE/UPLC–MS/MS Detection of Gemifloxacin Mesylate

Abstract

Eight molecularly imprinted polymers (MIPs) were synthesized for the determination of the antibacterial agent gemifloxacin mesylate (GFM). The polymers were prepared using GFM as a template, methacrylic acid (MAA) or 4-vinylpyridine (4-VP) as functional monomers, ethylene glycol dimethacrylate (EGDMA) as a cross linker, 2,2′-azobisisobutyronitrile (AIBN) as an initiator and a mixture of dimethylsulfoxide (DMSO)/acetonitrile (ACN) (1:1, v/v) as a porogen. The optimized polymer was utilized as a solid-phase extraction (SPE) sorbent material for GFM from different matrices. Different loading, washing and elution protocols were investigated. Quantitative analysis of the extracts was performed using a newly developed ultra-performance liquid chromatography–mass spectrometry (UPLC–MS/MS) method on an Acquity BEH C18 column (100 mm × 2.1 mm, particle size of 1.7 µm). The isocratic mobile phase was a mixture of methanol (MeOH)/water (H2O) with 0.1% formic acid (70:30, v/v), the flow rate was 0.3 mL min−1 and the column temperature was 40 °C. Lomefloxacin (LOM) was used as an internal standard. The developed method was validated based on the recommendations of the International Conference on Harmonization (ICH) and was found suitable for the extraction of GFM from a pharmaceutical drug preparation and spiked human urine samples. Recovery % values ranged from 90.24 to 112.8% with relative standard deviation (RSD) of less than 7%.