During the time I spent in Berkeley I had the honor to work on the beginning of the project leading to the portable system for highly sensitive multi-dimensional chemical analysis. This work included hyphenation of NMR with liquid chromatography separation using organic polymer monoliths. I have to admit, it was my first touch of NMR [...]
Generally, methacrylic acid is used as a charge-bearing agent for generation of electroosmotic flow in capillary electrochromatography. However, methacrylic acid has a significant effect on the morphology of the monolithic stationary phases based on styrene – divinylbenzene system as showed recently by group in Prague. The monolithic material prepared without methacrylic acid in the polymerization [...]
One column fits all was title of my poster presented at HPLC 2010 in Boston that described the preparation and characterization of hypercrosslinked monolithic stationary phases and their application in several chromatographic modes. We summarized poster’s results and submitted them as a paper in Journal of Chromatography A. Hypercrosslinking modification is not a new technique. [...]
Today, I would like to describe my favorite chromatographic books: from one I bought even before I (really) knew what chromatography is to one which has chapter with my name on it. Úvod do vysokoúčinné kapalinové kolonové chromatografie I am sorry to all of you who does not understand Czech language. This is my very [...]
Georges Guiochon pointed out in his excelent reivew about monolithic stationary phases four directions from which we can expect a serious improvement in (monolithic) columns performance. High temperature chromatography High temperature chromatography, which causes a reduction in the viscosity of the mobile phase. So far, monolithic stationary phases have not yet been used at high [...]
Although the monolithic stationary phases suitable for separations were introduced in the 1990s [1,2,3], the idea of using a “continuous block of the porous gel structure” as stationary phase was discussed in Analyst by R. L. M. Synge, A. J. P. Martin, and A. Tiselius as longs ago as in 1952. Both equilibrium and kinetic [...]
Because of lack of small pores it is difficult to separate small molecules with polymer monoliths in isocratic mode. We have prepared monolithic capillary columns and then hypercrosslinked them to afford a monolith containing an array of small pores [1]. This monolithic column affords good separation of uracil and alkylbenzenes in isocratic mobile phase mode [...]
Many applications of porous materials in areas such as catalysis, adsorption, ion exchange, chromatography, and solid phase synthesis rely on the intimate contact with a surface that supports the active sites. In order to obtain large surface area, a significant number of smaller pores should be incorporated into the polymer. Types of pores The most substantial contribution to the [...]
The generally accepted mechanism of pore formation in organic polymer monolihts during a typical polymerization in the presence of a precipitant is following [1,2]: The organic phase contains both monovinyl and divinyl monomers, initiator and porogenic solvent. The free-radical initiator decomposes at a particular temperature and the initiating radicals start the polymerization process in solution. Nuclei formation The polymers [...]
Analytical chemist. Amateur photographer. Occasional traveler. Lazy graphoman. Wannabe entertainer. Boring moralist ...
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Chromatographic articles