Matrix solid-phase dispersion extraction coupled with HPLC-diode array detection method for the analysis of sesquiterpene lactones in root of Saussurea lappa C.B.Clarke

We developed a reliable and effective method to determine costunolide and dehydrocostuslactone in the root of Saussurea lappa C. B.Clarke using matrix solid-phase dispersion (MSPD) extraction, HPLC separation and diode array detection (DAD). Several extraction parameters for the MSPD were optimized. Florisil was chosen as dispersing adsorbent with methanol as elution solvent. The ratio of Florisil to sample was selected to be 4:1 and no additional clean-up steps were needed. Linearities (r>0.9995) were determined to be in the range of 22.5-360.0 μg/mL for costunolide and 25.0-400.0 μg/mL for dehydrocostuslactone. Intra- and inter-day precisions were also determined with a relative standard deviation (RSD) less than 3.2%. The limits of detection were found to be 0.122 μg/mL for costunolide and 0.135 μg/mL for dehydrocostuslactone. The recoveries were in the range of 92.5-99.8% with relative standard deviations ranged from 1.2% to 3.5%. The proposed MSPD method required shorter time and lower solvent volume than maceration-ultrasonic and Soxhlet extraction methods.