Simultaneous determination of nine components in Yinhuang preparations by HPLC

Objective: To establish an HPLC method for simultaneous determination of nine components( chlorogenic acid,caffeic acid,luteoloside,baicalin,luteolin,wogonoside,baicalein,wogonin and oroxylin A) in Yinhuang preparations. Methods: The chromatographic separations were obtained on a Sepax GP- C18column( 250 mm × 4. 6mm,5 μm) with a gradient elution using the mixture of 0. 1% formic acid methanol solution and 0. 1% formic acid water solution at a flow rate of 1. 0 mL·min- 1. The detection wavelengths were respectively set at 275 nm( baicalin,wogonoside,baicalein,wogonin and oroxylin A),320 nm( chlorogenic acid and caffeic acid) and 350 nm( luteoloside and luteolin). The column temperature was set at 30 ℃. The injection volume was 20 μL. The constituents were confirmed by(-) electrospray ionization LC- MS. Results: All calibration curves were linear( r 0. 9997) over the tested ranges. The average recoveries( n = 9) ranged from 97. 1% to 103. 9% with RSD value below 3. 0%.The RSDs of within- run and between- run precision were below 1. 0% and 1. 7%,respectively. Conclusion: The established method is simple,fast,and with high precision,sensitivity and repeatability,which can be used efficiently in the quality control of Yinhuang preparations.