Goji berry, fruits of the plant Lycium barbarum L., has long been used as traditional
medicine and functional food in China. In this work, a simple and easy-operation on-line
concentration capillary electrophoresis (CE) for detection flavonoids in goji berry was developed
by coupling of field amplified sample stacking (FASS) with an electroosmotic (EOF)
pump driving water removal process. Due to the EOF pump and electrokinetic injection
showing different influence on the concentration, the analytes injection condition should
be systemically studied. Thereafter, the verification of the analytes injection conditions was
achieved using response surface experimental design. Under the optimum conditions, 86–
271 folds sensitivity enhancement upon normal capillary zone electrophoresis (CZE, 50
mbar × 5 s) were achieved for six flavonoids, and the detection limits ranged from 0.35 to1.82 ng/mL; the LOQ ranged from 1.20 to 6.01 ng/mL. Eventually, the proposed method was applied to detect flavonoids in 30 goji berry samples from different habitats of China;and the results indicated that the flavonoids were rich in the eluent of 30–60% methanol,which provided a reference for extraction of goji berry flavonoids.