Microwave-assisted aqueous two-phase extraction of alkaloids from Radix Sophorae Tonkinensis with an ethanol/Na2HPO4 system: Process optimization, composition identification and quantification analysis

Abstract A rapid method for simultaneous extraction and separation of multiple alkaloids from Radix Sophorae Tonkinensis (RST) was developed by microwave-assisted aqueous two-phase extraction (MAATPE) using the aqueous two-phase extraction system (ATPS) of ethanol/Na 2 HPO 4 as the extraction solvent. The effects of key factors on extraction yield were investigated by utilizing single-factor experiment coupled to response surface methodology (RSM). The regression model by RSM was significant (p  N -methylcytisine in RST were quantified in range of 0.493–10.284 mg/g with recoveries of 90.26–106.3% and RSD’s of 0.8–2.1%, respectively. Moreover, the MAATPE mechanism was explored using the different extraction systems in combination of scanning electron microscopy (SEM) morphological studies. Significant differences in extraction yield and cell rupture exhibited that the addition of the salt in the ethanol-water mixture not only improved the thermal and demixing effects, but also accelerated the mass transfer and biphasic extraction processes. MAATPE integrated the advantages of microwave-assisted extraction (MAE) and aqueous two-phase extraction (ATPE) was proved as a green, efficient and promising alternative to extraction of alkaloids from RST.