Extraction of L-synephrine by Bis(2-ethylhexyl)phosphoric acid/n-octanol Reversed Micelles

Abstract

In this study, reversed micelles of Bis(2-ethylhexyl)phosphoric acid/n-octanol was prepared to investigate the purification of L-synephrine in Citrus aurantium fruit crude extract. The reverse micellar system formed was confirmed with atomic force microscopy and the effect of important factors on extraction efficiency, such as the pH of the aqueous phase, molar ratio of water to surfactant, surfactant concentration, cationic ion concentration, and extraction time, was studied. Under the optimal operational conditions, the purity of L-synephrine was improved to be >85% and the total yield >98%. Mathematic analysis and experimental results exhibited that the extraction process in this system was effectuated mainly via electrostatic interactions between L-synephrine and the surfactant.