Molecular imprinted polymers stationary phases, preparation

Sellergren, B. Molecular imprinting by noncovalent interactions—enantioselectivity and binding-capacity of polymers prepared tmder conditions favoring the formation of template complexes. Makromolek. Chem.—Macromol. Chem. Phys. 1989, 190, 2703-2711. Kempe, M. Mosbach, K. Directed resolution of naproxen on a non-covalently molecularly imprinted chiral stationary phase. J. Chromatogr. 1994, 664, 276-279. 

Regarding the detection protocols used with capillary columns with molecularly imprinted stationary phases, on-column UV absorbance detection has been exclusively used. Some sort of open tubular area without imprinted polymer is normally prepared to perform detection. It has been shown, however, that UV detection can be performed through the imprinted polymer [39] in some cases. A nice feature with the photo-induced polymerisation procedure is that a part of the capillary column can be covered during the polymerisation reaction, thus preventing polymer being formed in that area. This is utilised to readily prepare detection windows on the MIP capillary columns. There is then no need for coupling of a second capillary to the imprinted polymer-filled capillary to be able to perform detection. 

Haginaka, J. Takehira, H. Hosoya, K. Tanaka, N. Molecularly imprinted uniformsized polymer-based stationary phase for naproxen. Comparison of molecular recognition ability of the molecularly imprinted polymers prepared by thermal and redox polymerization techniques. J. Chromatogr. A 1998, 816, 113-121. 

A number of novel stationary phases are commercially available now in bulk quantities for in-house packing or in prepacked preparative size columns. These media can be used to meet different separation needs, such as separation of compounds with polar functional groups, highly hydrophilic compounds, basic analytes, etc. The newest additions to the selective packing materials include custom-tailored molecular imprinted polymers. ... 

In Chapter 4, the authors discuss the noncommercial CSPs, their preparation, and the in-laboratory preparation (home coating) of the chromatographic plates by using these sorbents. Among the stationary phases discussed are cellulose, cellulose triacetate, cellulose tribenzoate, cellulose tricarbamate molecular imprinting polymers (MIPs), and jS-cyclodextrin ( -CD) bonded to the silica gel matrix. 

Molecular imprinting has recently attracted considerable attention as an approach to the preparation of polymers containing recognition sites with predetermined selectivity. The history and specifics of the imprinting technique pioneered by Wulff in the 1970s have been detailed in several excellent review articles [122-124]. Imprinted monoliths have also received attention as stationary phases for capillary electrochromatography. 

The molecular imprinting strategy can be applied for the recognition of different kinds of templates from small organic molecules to biomacromolecules as proteins. Some examples of separations investigated with MIP monoliths in CEC and LC are shown in Table 2. The influence of the imprinted monolithic phase preparation procedure and of the separation conditions on the selectivity and chromatographic efficiency have been widely studied [154, 157, 161, 166, 167, 192]. The performance of imprinted monoliths as chromatographic stationary phase has also been compared to that of the traditional bulk polymer packed column [149, 160]. It was shown that the monolithic phases yielded faster analyses and improved chiral separations. 

The preparation of polymers and other materials with molecularly imprinted cavities has now reached a high degree of sophistication. The application of these materials is becoming more and more interesting. First industrial applications of imprinted materials are envisaged, especially as stationary phases in chromatography, e.g., for the resolution of racemates. Other interesting applications can be seen in membranes and in sensors. 

Andersson, L.I. O Shannessy, D.J. Mosbach, K. Molecular recognition in synthetic polymers preparation of chiral stationary phases by molecular imprinting of amino acid amides. J. Chromatogr. 1990, 513, 167-179. 

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