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AIM: To study the distribution characteristics of steady-state trough concentration (C
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Objective To establish a method for the quantitative determination of sildenafil in aphrodisiacs by liquid chromatography-mass spectrometry (LC-MS). Methods Chromatography was carried on a Waters BEH C18 column (50 mmí2. 1 mm,1. 7 μm) with the column temperature being 35 ℃ and 0. 02 mol·L-1 ammonium acetate water solution (containing 0. 1% acetic acid)-acetonitril (7030) as the mobile phase at a flow rate of 0. 2 mL·min-1 . Determination was performed by multiple reaction monitoring mode in two channels,475→100,475→283,using electrospray ionization in positive ion mode. Results Sildenafil had a good linear relationship in the range of 0. 1986-1. 986 ng with the linear regression equation being Y=27 750X+15 232 (r=0. 995 2). The average recovery was 96. 6% with RSD being 1. 8% (n=9). The limits of quantitation and detection were 0. 04 ng and 0. 01 ng,respectively. Conclusion The determination results of 10 batches of samples show that the method is sensitive and accurate and can be used as an appropriate technique to detect sildenafil in aphrodisiacs.
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OBJECTIVE:To establish a RP-HPLC method for simultaneous determination of 4 flavonoids in Herba Euphorbiae Humifusae.METHODS:The samples were separated on Hypersil BDS C18 column(150 mm?4.6 mm,5 ?m)with CH3OH-0.3%H3PO4 as mobile phase(gradient elution)at a flow rate of 1.0 mL?min-1.The column temperature was maintained at 30 ℃ and the detective wavelength was set at 360 nm.RESULTS:The linear ranges of 4 flavonoids including rutin,quercetin,luteolin and kaempferol were 0.127 2～2.034 4 ?g(r=0.999 9),0.089 1～1.425 6 ?g(r=0.999 8),0.076 6～1.226 4 ?g(r=0.999 7),0.113 0～1.808 0 ?g(r=0.999 8)respectively,and their average recoveries were 97.6%,99.4%,98.1% and 101.9%,respectively with RSD at 0.94%,0.73%,0.99% and 1.34%,respectively(all n=9).CONCLUSION:This method was proved to be simple,accurate,reproducible and applicable for the quality control of Herba Euphorbiae Humifusae.