Hydrophilic molecularly imprinted chitosan microspheres based on deep eutectic solvents for micro-solid phase extraction of catechin

Abstract

Hydrophilic molecularly imprinted chitosan microspheres (HMICS) were synthesized using deep eutectic solvents (DESs)-(3-aminopropyl) triethoxysilane (APTES) as co-functional monomer for the extraction of catechin from green tea with micro-solid phase extraction (micro-SPE). Various factors were studied to optimize the extraction condition during extraction process. The actual extraction amount under the optimal conditions (amount of adsorbent (20 mg), type and volume of washing (acetone, 1.2 mL) and eluting solvent (acetone/acetic acid, 1.0 mL), extraction time (30 min), extraction temperature (40 °C), and sample pH (4)) were obtained at 97.06 mg·g⁻¹. The catechin recovery ranged with ranged with limit of detection (LOD) within 0.09–0.24 µg·mL⁻¹, and limit of quantification (LOQ) within 0.18–0.28 µg·mL⁻¹. From the experimental results in this system, the HMICS was proved to have higher extraction capacity, improving as a promising adsorbent for the extraction of catechin.

GRAPHICAL ABSTRACT

Keywords:

• Adsorbent
• deep eutectic solvents
• extraction
• hydrophilic molecularly imprinted chitosan
• micro-solid phase extraction

Acknowledgments

This study was supported by the Natural Science Foundation of Shandong Province (No. ZR2021QB060), Linyi University Doctoral Research Foundation grant funded by Linyi University (No. LYDX2020BS027), and the College Students' Innovation and Entrepreneurship Training Program by Linyi University (No. X202210452402).