Molecularly imprinted membranes with affinity properties for folic acid

The extraction of folic acid from aqueous solutions was proposed
through a novel procedure based on the membrane separation process
using the approach of molecular imprinting. Molecularly imprinted
membranes were prepared via the phase inversion technique using
poly(acrylonitrile-co-acrylamide) copolymer as the membrane material
and folic acid as the template molecule. Poly(acrylonitrile)-
based membranes were also prepared as the reference material.
Polymer composition, membrane preparation method, and the pH
used in the binding experiments were the parameters which mostly
influenced the recognition properties of the imprinted membranes.
In particular, the solvent evaporation method allowed to obtain
poly(acrylonitrile-co-acrylamide) imprinted membranes which at
pH 5.0 showed a specific binding capacity of 5.3 lmol=gmemb.
Corresponding blank membranes (prepared in absence of the
template molecule), only showed a poor non-specific binding of
1.0 lmol=gmemb. Polyacrylonitrile-based membranes showed lower
folic acid retention (1.5 lmol=gmemb. when prepared in the presence
of the template and 0.9 lmol=gmemb. when prepared in the absence
of the template).