Abstract: A high performance capillary zone electrophoresis (HPCZE) method was developed for the simultaneous separation and determination of rutin, kaempferol, isorhamnetin and quercetin in sea buckthorn. The effects of different electrophoresis conditions on separation efficiency were investigated. The running buffer was 20 mmol/L Na2B4O7-H3BO3 with 1.5 mg/mL β-cyclodextrin at pH 9.55, the detection wavelength was set at 370 nm, applied voltage 25 kV and injection time 5 s. Under these optimal conditions, rutin, kaempferol, isorhamnetin and quercetin could be fully separated each other within eleven minutes with good linearity in the range of 0.01 to 0.51, 0.05 to 0.93, 0.02 to 0.65, and 0.03 to 0.81 mg/mL, respectively and correlation coefficients between 0.997 1 and 0.999 1. The lowest detection limits were 5.05 × 10-5, 2.10 × 10-5, 3.75 × 10-5, and 1.31 × 10-5 mg/mL, respectively (RSN 3). The average recoveries of spiked samples were in the range 95.51% to 104.66%, with a relative standard deviation (RSD) lower than 3.92% (n 3). Under the optimized conditions, a mixture of four standard compounds and four active compounds in extracts of sea buckthorn three different producing areas were determined. The results showed that the total content of active compounds was the highest in seabuckthorn ürümqi, Xinjiang among three different producing regions, and lowest in the sample Wuwei, Gansu. Furthermore, the sample Lüliang, Shanxi had the highest quercetin content while the contents of kaempferol and isorhamnetin were the highest in the sample ürümqi, Xinjiang. This method is rapid, simple, accurate and reliable for the simultaneous detection of active compounds in sea buckthorn.

Key words: high performance capillary zone electrophoresis (HPCZE), rutin, kaempferol, isorhamnetin, quercetin, sea buckthorn