Cholesterol-based polymeric monolithic columns for capillary liquid chromatography

Cholesterol-based polymeric monolithic columns for capillary liquid chromatography. Part II

“…Interesting is the fact, that the intersection points are changing towards lower 222 temperatures with increasing of amount of cholesterol molecules on the silica surface 223 (coverage density of amino-cholesterol was 1.77 µmol/m 2 , while diamino-cholesterol -2.28 224 µmol/m 2 ) which trend could suggest that the amount of surface cholesterol is even larger on 225 the monolith. Such an observation would be consistent with our previously reported data 226dealing with the evaluation of hydrophobicity of these stationary phases[33]. The227temperature studies have also been performed for larger molecules, such as steroid hormones 228 (see section 3.4).…”

“…As it can be seen we 262 were able to successfully separate 13 PAHs in less than 7 minutes. Taking into account the 263 relatively low surface area of the described cholesterol monoliths (S BET = 77.60 m 2 /g, please 264 refer to our previous work[33]) this is a quite satisfactory result, as all 16 PAHs are not 265 always perfectly resolved on C 18 silica-based stationary phases. We tried the separate all of266 the 16 PAHs using isocratic elution, but strong hydrophobic interactions of the analytes with 267 the cholesterol functional groups caused very strong retention of PAHs, however without any 268 significant improvement of the resolution to that presented in the Fig.…”

“…In the first part of 119 our work we thoroughly described the methodology of preparation of such monolithic 120 capillary columns and the potential benefits arising from their use [33]. To obtain a polymeric 121 material we used a thermally initiated polymerization carried out directly in the fused silica …”

“…The temperature-dependent chromatographic experiments were performed using a system of The detailed procedure of preparation of the cholesterol-based monolithic capillary 172 columns has been reported previously [33]. Briefly, the following constituents ratios were The effect of temperature on retention factor k can be described by the van"t Hoff 202 relationship: …”

Current trends in the development of porous polymer monoliths for the separation of small molecules

“…Cholesteryl methacrylate has been synthesized and copolymerized with trimethylolpropane trimethacrylate to prepare novel type of monolithic stationary phase . At first, thorough optimization of the porogenic solvent composition has been performed.…”