RESUMO
Objective: To develop a novel method using high-performance capillary electrophoresis coupled with DAD (HPCE-DAD) for the simultaneous determination of 10 phenolic compounds (luteolin-7-O-glucoside, rutin, quercetin-3-glucoside, quercetin-3- rhamnoside, salicylic acid, luteolin, kaemferol, quercetin, gallic acid, and protocatechuic acid) in Bidens bipinnata. The extraction efficiency of above mentioned compounds was compared using six different ethanol/water solutions. Methods: The effects of pH value and concentration of buffer, applied voltage, and temperature on the separation were researched. The 10 compounds were baseline separated within 16 min in a 60 cm length capillary at a separation voltage of 25 kV with a running buffer consisting of 25 mmol/L borate (pH 9.5) at wavelength of 214 nm. Results: Excellent linearities of luteolin-7-O-glucoside, rutin, quercetin-3-glucoside, quercetin-3-rhamnoside, salicylic acid, luteolin, kaemferol, quercetin, gallic acid, and protocatechuic acid were observed at 5.0-120, 5.0-120, 5.0-120, 5.0-120, 1.0-120, 2.5-120, 5.0-120, 2.5-120, 2.5-120, and 2.5-120 mg/L, respectively. The detection limits were at 2.5, 2.5, 2.5, 2.5, 0.5, 1.0, 2.5, 1.0, 1.0, and 1.0 mg/L, respectively. The relative standard deviations (RSD) of precision were below 5.17% (n = 6). The mean recoveries for 10 phenolic compounds in B. bipinnata ranged from 94.4% to 105.8%, with RSD values of 0.32%-4.33%. Conclusion: The contents of luteolin-7-O-glucoside, rutin, quercetin-3- glucoside, quercetin-3-rhamnoside, salicylic acid, luteolin, kaemferol, quercetin, gallic acid, and protocatechuic acid in B. bipinnata are 95.04-105.84, 78.03-110.45, 96.45-177.96, 178.78-300.00, 62.06-66.54, 71.08-72.85, 77.39-95.30, 68.27-77.43, 68.47- 88.47, and 107.24-142.43 μg/g, respectively.
RESUMO
OBJECTIVE: To establish a high performance capillary electrophoresis method with diode array detection (HPCE-DAD) method for simultaneous determination of catalpol, aucubin, geniposide, acteoside and cinnamic acid in raw and processed Rehmanniae Radix. METHODS: 60 mmol · L-1 sodium borate was used as buffer solution (5% methanol, pH 9.5), uncoated fused silica capillary (64.5 cm × 75 μm, 56 cm of effective length) was used, separation voltage was 20 kV, detection wavelength was 210 nm, column temperature was maintained at 25°C, and sample was injected at 5 kPa × 6 s. RESULTS: Five index components showed good linearity (r > 0.9978) in the ranges of the tested concentrations, the average recoveries of the method were between 97.63%-103.03%. CONCLUSION: The method is simple, accurate and reproducible, and can be used for the quality control of Rehmanniae Radix.