Simultaneous determination of seven phenylethanoid glycosides in Cistanches Herba by a single marker using a new calculation of relative correction factor

Current quantitative analysis of multi-components by a single marker is usually performed by using liquid chromatography methods coupled with ultraviolet or mass spectrometry detection to afford the relative correction factors between reference standard and other components. However, low durability of the relative correction factors caused by different chromatographic system leading this approach lacking a high accuracy. In the present study, a simple but effective method was established by employing the absorption coefficient (E-1 cm(1%)) to calculate the relative correction factors instead of peak area or height. The absorption coefficient, a fundamental constant of physics, has been widely used for qualitative and quantitative analysis in Pharmacopoeia all over the world. According to the absorbance coefficient ratio between echinacoside and other compounds, the content of seven phenylethanoid glycosides in Cistanche deserticola and Cistanches tubulosa were determined simultaneously. The low standard method difference on quantitative measurement of seven compounds in Cistanches Herba between our method and the external standard method proved the consistency of the two methods. Using an ultra high performance liquid system, these seven bioactive phenylethanoid glycosides were baseline separated in 8 min. All the data suggested that the method was accurate and reliable for the determination of multi-components when authentic standard substances were unavailable.