Preparation and characterization of grafted imprinted monolith for capillary electrochromatography

Abstract

In this paper, a molecularly imprinted polymer (MIP) coating grafted to a trimethylolpropane trimethacrylate (TRIM) core material for CEC was reported. The core monolith was prepared with a solution of 20% (w/w) TRIM in a mixture of porogen and a polymerization precursor, which can generate a stable electroosmotic flow due to the formation of ionizable groups after postpolymerization hydrolization. Graft polymerization took place on the resultant TRIM monolith with a mixture of template, methacrylic acid, and ethylene glycol dimethacrylate. Strong recognition ability (selectivity factor was 5.83) for S-amlodipine and resolution of enatiomers separation (up to 7.99) were obtained on the resulting grafted imprinted monolith in CEC mode. The influence of CEC conditions on chiral separation, including the composition of mobile phase, pH value, and the operating voltages was studied. These results suggest that the method of grafted polymerization reported here allows a rapid development of MIP monolith once core materials with desired properties are available, and is a good alternative to prepare CEC-based monolithic MIPs.

Recent advances in capillary electrochromatography using molecularly imprinted polymers

“…As previously mentioned, the pseudostationary phase consisted in MIP‐microparticles prepared by the molecular crowding approach. Once again, using MIP‐grafted poly(TRIM) monolith offered a better R ( R s = 4.97) and separation factor (α = 2.35), but probably due to the heterogeneity of imprinted sites a broad peak of T enantiomer was observed. The T ( S ‐OFX) peak shape was not improved even when an LiqCr MIP‐coating column with low level of cross‐linking was employed .…”

“…). An even shorter analysis time (<7 min) with similar selectivity ( R s = 4.62, α = 1.29) was achieved using an MIP coating grafted on a TRIM core monolith . Unfortunately, the gain in the analysis time is hardly justified by the increased column preparation time: 15 h for TRIM core monolith synthesis and an additional 3 h for MIP‐coating polymerization.…”

“…In spite of the highlighted advantages of MIP‐based pseudostationary phases (simple, fast, and reproducible synthesis, no column ageing and decrease of analytical performances due to strong adsorption, improved mass transfer), most probably due to the more simple analytical method development and optimization, the use of MIP stationary phases is still more prevalent in the enantioseparation of small drug molecules: AML , tyrosine , neurotransmitters , ractopamine , NAP , KET , atenolol, and sulpiride .…”

Current trends in the development of molecularly imprinted polymers in CEC

“…The MIP coatings anchored covalently onto the surface of silica monolith in capillary for HPLC have been reported . Recently, Wei et al successfully synthesized MIP coatings grafted to a trimethylolpropane trimethacrylate (TRIM) core material monolith for CEC utilizing pendant double bonds on poly‐TRIM. A polymerization precursor, γ‐MPS, was adopted as comonomer, which does not interfere with the formation of defined imprints and can generate a stable EOF due to the formation of ionizable groups after postpolymerization hydrolization.…”

Liquid crystal-based molecularly imprinted nanoparticles with low crosslinking for capillary electrochromatography

“…Up to now, there are mainly three formats of MIP that can be applied to CEC, namely the monolith [13][14][15][16][17][18][19], the coating [20][21][22][23][24] and particle-based technique [25][26][27][28][29][30][31][32][33]. To extend the application of liquid crystal MIP, liquid crystalline MIP nanoparticles were tried for enantiomers separation in CEC mode.…”