A quantitative high performance liquid chromatography-tandem mass spectrometry (LC/MS/MS) was developed to analyze the constituents of podophyllin. Chromatographic separation was performed on a Cosmosil 5C18-MS (25 cm × 4.6 mm I.D., 5 μm) reverse phase column using a gradient of mobile phase (0.25% formic acid-methanol). The column effluent was split 2: 3 into the photodiode detector and tandem mass spectrometer. Podophyllotoxin, quercetin and kaempferol in podophyllin were identified by
daughter ion scan mode and then determined their contents by multiple-reaction monitoring (MRM) mode. The limits of detection and quantitation for podophyllotoxin, quercetin and kaempferol were 2.40, 8.01; 2.94, 9.87 and 3.10, 10.2 ng/mL, respectively. The relative standard deviations of intraday and interday analyses for podophyllotoxin, quercetin and kaempferol ranged from 0.52- 6.01% and 2.48-9.88%, respectively. The mean recoveries for podophyllotoxin, quercetin and kaempferol were 101.4%, 98.3% and 98.7%, respectively. The developed LC/MS/MS method was suitable for the simultaneous determinations of podophyllotoxin, quercetin and kaempferol in podophyllin.