Ultra-sensitive detection of cadmium and lead in water using crown ether gel electromembrane extraction coupled with miniaturized electrochemical system

• Published in: Microchemical journal 2024-11, Vol.206, p.111449, Article 111449
• Main Authors: Ratih Purwaningsih, Dwi, Pengsomjit, Untika, Aly Saad Aly, Mohamed, Darwish, Ibrahim A., Karuwan, Chanpen, Kraiya, Charoenkwan
• Format: Article
• Language: English
• Subjects: Agarose gel; Cadmium; Crown ether; Electrochemistry; Electromembrane extraction; Lead; Water analysis
• ISSN: 0026-265X
• DOI: 10.1016/j.microc.2024.111449

[Display omitted] •18C6@G-EME method shows 120 times higher sensitivity than direct measurements.•Selective detection of Cd2+ and Pb2+ ensures reliable environmental analysis.•Achieved ultra-sensitive detection limits of 0.10 µg L−1 for Cd2+ and 0.19 µg L−1 for Pb2+.•Achieves rapid analysis with minimal sample preparation.•Adaptable to other ions detection and promising for further miniaturization and portability. This study presents the development of an electrochemical technique combined with gel electromembrane extraction (G-EME) for the simultaneous detection of cadmium and lead in environmental water samples. Crown ether (18C6) was added to the gel as a complexing agent and cationic carrier. The electrochemical responses were evaluated using differential pulse anodic stripping voltammetry (DPASV) across various pH levels and deposition times. The most sensitive response (acetate buffer pH 4, deposition time 90 s) was selected for the development of the G-EME process. By applying a 30 V electrical potential across the gel membrane containing 1 % (w/v) of 18C6 for 10 min, positively charged Cd2+ and Pb2+ ions migrated from the donor phase (pH 5.0) through the 18C6@gel membrane (pH 5.0) into the acceptor phase (pH 5.0). This resulted in a linear range from 0.3 to 5 µg/L for Cd2+ and 0.5 to 5 µg/L for Pb2+, with detection limits of 0.10 µg/L and 0.19 µg/L, respectively— up to 120 times more sensitive than direct electrochemical measurements. Furthermore, the proposed technique maintained selectivity for cadmium and lead, despite the presence of other potential heavy metal ions in the environment.