Interfacing liquid-phase microextraction with electrochemical detection: A critical review

The increasing interest in the development of rapid and efficient liquid-phase microextraction (LPME) approaches has led to a strong demand of fast, portable and decentralized detection methods as compelling alternatives to standard chromatographic and atomic spectrometric techniques. For this purpose, the coupling of LPME to electrochemical detection (ECD), including mostly cyclic, differential pulse, and stripping voltammetric techniques, has been explored in recent years for sensing of various analytes, including ions and drugs, in samples of varying matrix complexity. This review is aimed at critically surveying the current state of the art of the LPME-ECD hyphenation within the timeframe of 2010–2022 by pinpointing (i) smart configurations for in-situ micro-extraction and detection, (ii) experimental parameters for amelioration of analyte extractability and detectability, (iii) the compatibility of the solvent and analyte-enriched phase with the ensuing detection step, and (iv) analytical strategies and guidelines to cope with sensitivity, and selectivity demands. In addition, analytical validation and real life application of the LPME-ECD methods are critically evaluated and some future perspectives in the field of 3D printing and the development of integrated fluidic platforms are provided. •Coupling of LPME for sample clean-up and/or analyte preconcentration with ECD.•Compatibility of extraction/acceptor phase with ECD.•Configurations for concomitant LPME and ECD and on-drop analysis.•Tricks and tips to solve sensitivity and selectivity issues in LPME-ECD.•Gaps in analytical validation methods are identified.