Introduction of agarose gel as a green membrane in electromembrane extraction: An efficient procedure for the extraction of basic drugs with a wide range of polarities

- Agarose gel as a green membrane was used in electromembrane extraction (EME).
- Simultaneous extraction of basic drugs with wide ranging polarities.
- Highly polar drug was efficiently extracted without using any carrier or ion pair reagents.
- Possibility for fabricating membranes of different shapes and thicknesses.
- Use of a completely safe membrane that makes the method environmentally-friendly.

Developing green methods for analyte extraction is one of the most important topics in the field of sample preparation. In this study, for the first time, agarose gel was used as membrane in electromembrane extraction (EME) without using any organic solvent, for the extraction of four model basic drugs (rivastigmine (RIV), verapamil (VER), amlodipine (AML), and morphine (MOR)) with a wide polarity window (log P from 0.43 to 3.7). Different variables playing vital roles in the proposed method were evaluated and optimized. As a driving force, a 25 V electrical field was applied to make the analyte migrate from sample solution with pH 7.0, through the agarose gel 3% (w/v) with 5 mm thickness, into an acceptor phase (AP) with pH 2.0. The best extraction efficiency was obtained with an extraction duration of 25 min. With this new methodology, MOR with high polarity (log P = 0.43) was efficiently extracted without using any carrier or ion pair reagents. Limits of detection (LODs) and quantification (LOQs) were in the ranges of 1.5-1.8 ng mL−1 and 5.0-6.0 ng mL−1, respectively. Finally, the proposed method was successfully applied to determine concentrations of the model drugs in the wastewater sample.