A hollow porous molecularly imprinted polymer as a sorbent for the extraction of 7 macrolide antibiotics prior to their determination by HPLC-MS/MS.

A hollow porous molecularly imprinted polymer (HPMIP) is described for use in dispersive solid phase extraction of macrolide antibiotics (MACs). The HPMIP was prepared by using spiramycin as the template, methacrylic acid as the functional monomer, and mesoporous MCM-41 (Mobile Composition of Matter No. 41; with a size of about 100 nm) as a sacrificial support. The sorbent was characterized by Fourier transform infrared spectrometry, transmission electron microscopy, nitrogen adsorption and thermo-gravimetric analysis. Several parameters affecting the extraction efficiency were optimized. The material has a large surface area (359 m2·g-1), and most recognition sites are located on the surface of the HPMIPs. This results in high binding capacity (120 μmol·g-1) and fast binding (20 min) in comparison to either MCM-41-core surface MIPs or solid MIPs. The method was applied to the extraction of the MACs azithromycin, spiramycin, tilmicosin, tylosin, clarithromycin, roxithromycin and josamycin from spiked honey. The recoveries, determined by HPLC-MS/MS, ranged from 88.0% to 117% at the three spiking levels tested (1, 5 and 20 μg·kg-1). Intra-day and inter-day assay precision at three spiking levels are <10.7% (for n = 6) and 12.6% (n = 3), respectively. The limits of detection are between 3 and 17 ng·kg-1. This indicates the superiority of the method in selective extraction of macrolides even from complex matrices. Graphical abstract Hollow porous molecularly imprinted polymers using spiramycin as the template are shown to be viable dispersive solid phase extraction adsorbents for selective enrichment of macrolide antibiotics in honey products prior to their quantitation by HPLC-MS/MS.