The progress of the cyclic strategy in separation and detection.

Analytical chemistry is undergoing a transformation from the traditional linear model to a cyclic model, driving separation and detection technologies toward greater efficiency and sustainability. The core lies in introducing the temporal dimension into the separation and detection process through the cyclic strategy. This review discusses the implementation of the cyclic strategy in separation and detection technologies, beginning with an explanation of two fundamental modes including macroscopic flow cycling and microscopic reaction cycling, along with an analysis of the energy and key device requirements. Furthermore, it explores the application of the cyclic strategy in sample preparation, chromatographic separation, electric field-driven separation, as well as in spectrum, electrochemical and mass spectrometry detection. Typical cases demonstrate that by incorporating the temporal dimension, the cyclic strategy significantly enhances separation efficiency, detection sensitivity, information dimensionality, dynamic monitoring capabilities and process sustainability within confined spaces and limited resources. Then the review outlines future challenges and potential directions for cyclic strategies in separation and detection, offering forward looking perspectives for further research. This review aims to clarify that the cyclic strategy represents not merely a collection of technical methods, but a methodological framework that leverages spatiotemporal synergy to address future challenges in complex analytical systems.