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 C₁₈ column (150 ¥ 4.6 mm, 5 mm) 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 © 2010 John Wiley & Sons, Ltd.