Synthesis, recognition characteristics and properties of l-3-n-butylphthalide molecularly imprinted polymers as sorbent for solid-phase extraction through precipitation polymerization.

L-3-n-butylphthalide molecularly imprinted polymers (MIPs) were synthesized using l-3-n-butylphthalide as template molecule, acrylamide as functional monomer, ethylene glycol dimethacrylate as cross-linking agent, and acetone as the porogenic solvent through precipitation polymerization. The non-imprinted polymers (NIPs) were prepared with the same procedure, but with the absence of template molecule. The optimum preparation conditions of the MIPs such as the functional monomer, the porogenic solvent, the molar ratio of the template to the functional monomer and the molar ratio of the template to the cross-linker were investigated in detail. Prior to the polymerization, the molecular simulation with the computer-aided design was used to help choose a suitable polymerization porogen for the molecularly imprinted pre-assembled system and study the interactions between l-NBP and the functional monomers. The synthesized polymers were characterized with FTIR and SEM to observe their structures as well as the morphologies, and their adsorption properties were respectively evaluated by static and dynamic adsorption as well as selectivity experiments. Scatchard analyses revealed that there were high and low affinity sites formed in the MIPs, which elucidated good affinity to l-NBP in the ethanol system. The adsorption capacity of the MIPs for l-NBP was 3.561 mg g(-1), with an imprinting factor (α) of 2.321 when compared with that of the NIPs. Scatchard analysis illustrated that the binding sites with affinity for l-3-n-butylphthalide molecules were formed in the prepared MIPs.