HPLC-MS analysis of sennosides A and B in aqueous extracts of Sennae folium prepared by a new microwave extraction method

A new, simplified open-vessel microwave extraction (OVME) method with solid-phase extraction (SPE) for sample clean-up has been developed for specific investigation of sennosides A and B. Aqueous extracts of senna leaves ( Senna folium ) were prepared by different methods, including classic pharmacopoeial methods: concoction, infusion, and ultrasound extractions. The different extraction methods were compared by analysis of the sennosides A and B in the samples with a modified enantiomer-selective reversed-phase high-performance liquid chromatographic-tandem mass spectrometric method. HPLC was performed with a 4.6 mm × 150 mm, 3.5-µm particle C 8 column and simple gradient elution. The benefit of open-vessel microwave extraction is discussed.