Chinese Journal of Applied Chemistry (应用化学) 2013/30:12 PP.1489-1493
NaPF6 (as an ion-pairing agent) was added to the extraction solution of Rhizoma coptidis and Cortex phellodend containing [C6MIM][Br](as hydrophilic ionic liquid(IL)). A cloudy solution formed as a result of the formation of fine droplets of [C6MIM][PF6]. After centrifugation, the sedimented phase enriched with alkaloids was analyzed by HPLC with UV detection. In this method, several important parameters, such as the type and volume of ILs, the amount of NaPF6, solution pH, extraction time and centrifugation time, influencing the extraction efficiency of IL-ISFME(in situ solvent formation microextraction) were optimized. Under optimal conditions, berberine, palmatine and coptisine exhibit good linearity, with correlation coefficients of 0.9998, 0.9996 and 0.9997, respectively, a linear range of 1~2000 μg/L and the detection limit of 0.5 μg/L. The spiked recovery for each analyte is in the range of 96.52%~104.34%. The experimental results indicate that the proposed method is successfully applied to the analysis of three alkaloids in Rhizoma coptidis and Cortex phellodend.
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