[Exploring correlation between molecular state and nanofiltration mass transfer process of synephrine from Citrus aurantium].

Based on the solution-diffusion effect and the charge effect theory in nanofiltration separation, the correlation between initial concentration and mass transfer coefficient was constructed to establish a mathematic model of synephrine in mass transfer process and verify its applicability. The experimental results showed that there was a linear relationship between operation pressure and membrane flux. Meanwhile, the membrane flux was gradually decayed with the increase of solute concentration. Besides, mass transfer coefficient and initial concentration of synephrine showed power function correlation with each other by solution-diffusion effect and the charge effect, and the regression coefficients were greater than 0.9. The mass transfer coefficient of dissociation synephrine was less than that in the state of free and free-dissociation. Moreover, on the basis of power function relationship between mass transfer coefficient and initial concentration, the results showed that the predicted rejections of synephrine from Citrus aurantium water extract by use of the mathematical model approximated well to real ones, verifying that the model was practical and feasible. The unclear separation mechanism of nanofiltration for alkaloids was clarified preliminary by the predicted model of nanofiltration separation with synephrine as the example, providing theoretical and technical support for nanofiltration separation, especially for traditional Chinese medicine with alkaloids.