Three-step anionic micelle-to-cyclodextrin stacking for toxic alkaloids analysis in food and herbal samples using citric acid-assisted capillary zone electrophoresis

A novel three-step anionic micelle–to–cyclodextrin stacking method, facilitated using citric acid–assisted capillary zone electrophoresis, was established for enrichment and detection of cationic pyrrolizidine alkaloids (PAs) in traditional herbs and food samples. In this context, several parameters influencing preconcentration efficiency of the method were investigated, including the type and concentration of anionic surfactants and cyclodextrins (CDs), the sodium dihydrogen phosphate concentration in sodium dodecyl sulfate, CD solution, and sample solutions; and the sample injection time. Furthermore, the limits of detection of crotaline, senecionine, and senecionine N-oxide were found to be 0.006–0.009 μg/mL, with 49–96-fold sensitivity enhancement compared to that of the conventional injection method. The proposed method achieved excellent linearity (R 2  = 0.999) for the target analytes. Under optimal conditions, the method successfully enriched and analyzed two real-world samples, Senecionis scandentis Herba and chrysanthemum honey. The developed method has been adopted to detect and enrich three PAs in successfully.