Cyclodextrin-assisted vortex dispersive solid-phase extraction coupled with sweeping-field amplified sample stacking...

Simultaneous multi-component analysis of trace-level weakly ionized analytes in complex matrices remains a critical challenge for capillary electrophoresis (CE). To address this, this study developed a novel green analytical strategy by integrating cyclodextrin vortex-assisted dispersive solid-phase extraction (CD-VA-DSPE) with CD-assisted sweeping-field amplified sample stacking (CD-sweeping-FASS) in micellar electrokinetic chromatography (MEKC). The core innovation lies in the dual role of hydroxypropyl-β-cyclodextrin (HP-β-CD) as both an extraction solvent and a pseudostationary phase, enabling a seamless integration of sample preparation and online enrichment. Using the traditional Chinese medicine "Wenyangxiaozheng formula" as a model, the optimized method achieved baseline separation of four target components (lobetyolin, echinacoside, acteoside, calycosin), marking the first demonstration of CD-sweeping-FASS in MEKC for phytochemical analysis. Method validation demonstrated excellent linearity (r ≥ 0.9992) over a concentration range of 1-100 µg mL⁻¹, with limits of detection (LODs) of 0.02-0.05 µg mL⁻¹. The precision was satisfactory (intra- and inter-day RSDs < 2.98 %). Remarkably, compared with conventional CE injection, the method achieved sensitivity enhancements of 106- to 208-fold. With the successful application in quantitative analysis of target components (0.46-9.93 µg mg⁻¹) in both herbal formulations and spiked rat serum, the proposed approach establishes itself as a high-throughput and sustainable solution for the simultaneous determination of trace weakly ionized compounds in complex matrices.