Analysis of the Sorption Properties of Molecularly Imprinted Polymers as Materials for Potential Monitoring of the Amount of Amoxicillin in an Aqueous Environment

ABSTRACT

This work describes a procedure for obtaining molecularly imprinted polymers (MIPs) toward amoxicillin based on methyl methacrylate. To characterize the polymers synthetized, physicochemical and sorption properties were analyzed. The influence of the main parameters on the adsorption efficiency was investigated (the monomers composition of materials, contact time, initial concentration, and regeneration conditions). The adsorption isotherms were fitted by Freundlich, Langmuir, and Dubinin–Radushkevich models. Pseudo-first-order, pseudo-second-order, intraparticle diffusion, and second Fick’s law models were used to fit the kinetic data. Molecularly imprinted polymer which was obtained using 5 wt.% of amoxicillin in relation to the monomers, characterized by the highest sorption value of 4.8 mg/g. This polymer showed selective properties in competition with gentamicin and norfloxacin. Furthermore, in the case of testing imprinted polymers in real samples, materials with an imprint were characterized by higher sorption values compared to those without an imprint (3.27 and 2.02 mg/g, respectively). For the first time, for this type of MIP, we conducted research for regenerating. Water solutions with pH 3 or 9, 1% acetic acid, and ethanol were tested as regeneration solutions. Molecularly imprinted polymer regeneration for the most effective regeneration solution was carried out on SPE columns, allowing a 94% cleaning of the sorption material.

KEYWORDS:

• Amoxicillin
• molecularly imprinted polymers
• sorption analysis
• regeneration method

Acknowledgments

The authors thank Małgorzata Ulatowska for performing the TGA analysis.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions statement

Conceptualization and design, JoWo and KSK; methodology JoWo, DR and KSK.; formal analysis, JoWo and KSK; investigation, JoWo and KSK; resources, JoWo and KSK.; data curation, JoWo and KSK; writing – original draft preparation, JoWo, DR and KSK; writing – review and editing, JoWo, DR and KSK; visualization, JoWo and KSK; supervision, JoWo and KSK; funding acquisition, JoWo and KSK, HPLC methodology and analysis, DR; SEM pictures, JuWi. All authors have read and agreed to the published version of the manuscript.

Data availability statement

The data presented in this study are available on request from the corresponding author.

Additional information

Funding

This research was funded by a statutory activity subsidy from the Polish Ministry of Science and Higher Education for the Faculty of Chemistry of Wroclaw University of Science and Technology.