Recovery of the Template in Molecular Imprinting: Liquid-Phase Microextraction or Electromembrane Extraction?

Molecular imprinting still faces the big challenge of template recovery, and the development of efficient template recovery methods is of great significance for the green synthesis of MIP. Herein, the performance of liquid-phase microextraction (LPME) and electromembrane extraction (EME) for template recovery was investigated for the first time using sulfamethazine as the model template. Under the optimal extraction conditions for low-concentration sulfamethazine using small-volume devices, the recovery of high-concentration sulfamethazine by large-volume LPME could still reach 89.9%, while the recovery by large-volume EME decreased sharply from 94.0% to 32.1%, which could be improved to 74.7% by increasing the extraction voltage. High recoveries of 88.1% and 72.6% were achieved for the actual MIP eluent using large-volume LPME and EME, respectively. This comparison of LPME and EME under different application scenarios will provide guidance for the rational selection of membrane-based microextraction techniques for the efficient recovery of templates in molecular imprinting.