Abstract:

Bis(2-ethylhexyl)phosphoric acid(P204)/n-octanol reversed micelle system was prepared to extract L-synephrine in Citrus aurantium fruit crude extract. The extraction mechanism as well as influencing factors including the pH of the aqueous phase, water content(W0), surfactant concentration, and extraction time were studied. P204/octanol reversed micelles was observed by AFM. The optimal extraction conditions determined via a series of experiments are as follows: aqueous phase pH=6.5, water content(W0)=15, surfactant concentration=0.08 mol/L, and extraction time=15 min. Under the optimized conditions, the one-time L-synephrine extraction rate reaches 68.0%. The mathematical model to fit the relationships of L-synephrine extraction rate with aqueous phase pH and surfactant concentration is also discussed.

Key words: L-synephrine, bis(ethylhexyl)phosphoric acid, reverse micelle, extraction