Electrochemical Detection in Electromembrane Extraction: A Critical Review of Principles, Challenges, and Recent Advances

Electromembrane extraction (EME) combined with electrochemical detection (ECD) provides a selective and sensitive strategy for enriching electroactive analytes in complex biological, environmental, and food matrices. This review critically summarizes recent advances in EME-ECD, with particular emphasis on voltammetric techniques, electrode surface engineering, and different degrees of system integration, ranging from offline configuration to fully online platforms. Reported applications include the determination of heavy metals, pharmaceuticals, and environmental pollutants, demonstrating the versatility of this approach. Despite considerable progress, several limitations continue to hinder its broader adoption, including dependence on offline detection, limited electrode stability, and insufficient validation using real-world samples. Additional concerns include methodological inconsistencies, overstated performance claims, and limited comparison with established chromatographic techniques. Promising future directions include microfluidic integration, multi-analyte electrode arrays, durable nanostructured electrode materials, and the application of machine learning for method optimization. The development of standardized protocols, certified reference materials, and lifecycle assessments will be essential for improving reproducibility, reliability, and sustainability. Continued interdisciplinary innovation is expected to advance EME-ECD toward a robust analytical platform for environmental, clinical, and food safety monitoring.