Abstract: Objective To establish a liquid chromatography-multiple-reaction monitoring cubed（LC-MRM³） methods for the simul-taneous determination of three cardiotonic alkaloids in Chinese herbal medicine and medicinal liquor（Oleandrin,Adynerin and Higenamine）. Methods The samples were extracted with 80% methanol,diluted with 30% acetonitrile,and then directly injected. Gradient elution was performed on a Phenomenex Kinetex C₁₈ chromatographic column（100×2.1 mm,2.6 μm）,and after separation, detected using the LC-MRM³ mode. Results The three alkaloids showed good linear relationships within their respective concentration ranges（r>0.999）. The detection limits in medicinal liquor samples ranged from 0.019 to 0.071 μg/L,for Chinese herbal medicine samples,the detection limits ranged from 0.006 to 0.022 μg/kg. The spike recovery rate was 90.31%-97.92%,with a relative standard deviation of 1.14%-2.73%（n=6）. Compared to the traditional method liquid chromatography-multiple-reaction monitoring（LC-MRM）,the LC-MRM³ method enhanced the detection sensitivity by an order of magnitude and allowed for simple sample preparation without the impact of matrix effects. Qualitative results were further confirmed through multi-stage mass spectrometry（MS³） scanning. The quantitative results of LC-MRM³ were essentially consistent with those of LC-MRM. Conclusion This method is simple,fast,and accurate,and can be used for the simultaneous detection of three cardiotonic alkaloids in Chinese herbal medicine and medicinal liquor.

Key words: Oleandrin, Adynerin, Higenamine, LC-MRM³