Molecular imprint polymers as highly selective stationary phases for open tubular liquid chromatography and capillary electrochromatography

Abstract

Chiral separations employing molecular imprint polymer (MIP) stationary phases in both open tubular liquid chromatography (OT-LC) and capillary electrochromatography (OT-CEC) are demonstrated. MIPs are highly crosslinked polymers containing spatial and functionality memory of template molecules which provide a higher degree of selectivity when used as stationary phases for chromatographic separations. Thin films of molecular imprinted polymers bonded to the inner walls of 25 microm ID fused-silica capillaries were prepared using an in situ polymerization technique developed in our laboratory that allows the use of conventional fused-silica capillaries with polyimide outer coatings. The success rate in preparing such open tubular columns was about 70%. Methacrylic acid and 2-vinyl pyridine were chosen as functional monomers, and either ethylene dimethacrylate or trimethylol propane trimethacrylate was used as the crosslinker. Toluene was employed as the porogen. Effects of polymerization conditions on column preparation and chromatographic performance were studied. Enantiomeric separations of D- and L-dansyl phenylalanines were achieved in both OT-LC and OT-CEC modes with good selectivity and efficiencies. Both types of separations may be performed on the same column using a single commercial instrument.

Analytical separations in open‐tubular capillary electrochromatography

“…This gives rise to a material that is filled with cavities, and one that is complementary in size, shape, and chemical functionality to the imprint molecule. These cavities enable the polymer to rebind the original template molecule [98,99,189,191,[193][194][195][196][197].…”

Chiral separation by chromatographic and electromigration techniques. A Review

“…This approach is advantageous with respect of circumventing packing of the columns. Tan and Remcho [192] reported the preparation of a capillary coated with a polymer MIP using Dns-l-Phe as template for chiral open-tubular LC and CEC of Dns-Phe. A multi-step swelling polymerization technique using water as suspension medium was developed by Haginaka et al [184].…”

Silicate entrapped columns — new columns designed for capillary electrochromatography

“…Recently, much effort toward the synthesis and use of stationary phases based on MIP in the open-tubular, packed and monolithic formats has been documented [17,18]. Using a packing material produced at Seton Hall University by bulk polymerization of an L-dansyl phenylalanine imprinted polymer, followed by grinding and sieving, we have packed and entrapped a column as Electrophoresis 1999, 20, 50±56…”