Hydrophobic‐hydrophilic monolithic dual‐phase layer for two‐dimensional thin‐layer chromatography coupled with surface‐enhanced Raman spectroscopy detection

Abstract

Hydrophobic-hydrophilic monolithic dual-phase plates have been prepared by a two-step polymerization method for two-dimensional thin-layer chromatography of low-molecular-weight compounds, namely, several dyes. The thin 200 μm poly(glycidyl methacrylate-co-ethylene dimethacrylate) layers attached to microscope glass plates were prepared using a UV-initiated polymerization method within a simple glass mold. After cutting and cleaning the specific area of the layer, the reassembled mold was filled with a polymerization mixture of butyl methacrylate and ethylene dimethacrylate and subsequently irradiated with UV light. During the second polymerization process, the former layer was protected from the UV light with a UV mask. After extracting the porogens and hydrolyzing the poly(glycidyl methacrylate-co-ethylene dimethacrylate) area, these two-dimensional layers were used to separate a mixture of dyes with great difference in their polarity using reversed-phase chromatography mode within the hydrophobic layer and then hydrophilic interaction chromatography mode along the hydrophilic area. In the latter dimension only the specific spot was developed further. Detection of the separated dyes could be achieved with surface-enhanced Raman spectroscopy.

Macroporous Polymer Monoliths in Thin Layer Format

“…Svec et al used the procedure based on application of 20% TMSPMA solution in ethanol adjusted with acetic acid to pH 5 for 2 h [41] or later for 30 min [50]. Zheng et al corresponded the application of 20% TMSPMA solution in ethanol overnight [51]. In our group, we used the silanization with 15% TMSPMA solution in toluene for 12-20 h [49,52,53].…”

“…The preparation of dual-phase polymer monolithic layers for 2-D TLC requires the application of some additional steps. For instance, Zheng et al developed the method for preparation of dual monolithic phase consisting of two polymers with different hydrophilic-hydrophobic properties, namely poly(GMA-co-EDMA) and poly(BMA-co-EDMA) [51]. In that case, authors initially synthesized a layer of poly(GMA-co-EDMA) monolith and cut and removed a section of the synthesized polymer.…”

“…The combination of two polymers with different nature, namely poly(BMA-co-EDMA) and hydrolyzed poly(GMA-co-EDMA), was realized by Zheng et al [51]. Separation using hydrophobic poly(BMA-co-EDMA) can be achieved by reversed-phase mode of TLC, whereas hydrolyzed poly(GMA-co-EDMA) allows the realization of hydrophilic separation mode.…”

Recent advances in the preparation of adsorbent layers for thin‐layer chromatography combined with matrix‐assisted laser desorption/ionization mass‐spectrometric detection

“…In Ref. , hydrophobic‐hydrophilic monolithic dual‐phase plates have been prepared by a two‐step polymerization method for 2D TLC of low‐molecular mass compounds, namely, several dyes. The thin 200 μm poly(GMA‐co‐EDMA) layers attached to microscope glass plates were prepared using a UV‐initiated polymerization method within a simple glass mold.…”

Some factors affecting pore size in the synthesis of rigid polymer monoliths: Theory and its applicability

“…The transparency of a mold and its thickness are the limitations for such kind of polymerization. Therefore, photopolymerization is mostly applicable for synthesis of capillary monolithic columns 40 and monolithic layers for thin‐layer chromatography 41 or microarrays 27 . The light intensity, nature, and concentration of the initiator are the key factors affecting the rate of polymerization.…”