Simultaneous Quantification of 14 Bioactive Constituents in Forsythia Suspensa by Liquid Chromatography-Electrospray Ionisation-Mass Spectrometry

Introduction - Forsythia suspensa is a commonly used traditional Chinese medicine including phenylethanoid glycosides, lignans, flavonoids, terpenes and volatile oils. Quantification of multi-components is important for the quality control of Forsythia suspensa. Objective - To establish a liquid chromatography-electrospray ionisation-mass spectrometry method for simultaneous quantification of 14 bioactive constituents of Forsythia suspensa in different places of China and different parts of this herb. Methodology - The optimal chromatographic conditions were achieved on a Kromasil C-18 column (150 x 4.6 mm, 5 mu m) with gradient elution of methanol, acetonitrile and 0.1% formic acid in 27 min. Detection was performed in negative ionisation mode by monitoring the precursor-product combination in multiple reaction monitoring (MRM) mode. The validation of the method included tests of linearity, sensitivity, precision, repeatability, stability and accuracy. Results - All calibration curves showed good linear regression (r>0.9990) within test ranges. The established method showed good precision and accuracy with overall intra-day and inter-day variations of 0.7-4.3 and 1.1-3.9% respectively, and overall recoveries of 96.65-101.2% for the compounds analysed. Conclusion - The proposed method was successfully applied for the quantitative analysis of 14 constituents in 12 Forsythia suspensa samples. Copyright (C) 2010 John Wiley & Sons, Ltd.