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K. N. Smirnov, I. A. Dyatchkov, A. V. Pirogov, O. A. Shpigun
Influence of the synthesis pressure on the chromatographic
properties of poly(divinylbenzene-co-ethylvinylbenzene-co-2-hydroxyethyl
methacrylate) monolithic columns
Abstract
Monolithic columns based on copolymer
of divinylbenzene (DVB), ethylvinylbenzene (EVB) and 2-hydroxyethyl
methacrylate (HEMA) were prepared and applied to the separation of
low-molecular-weight aromatic compounds. The monoliths were synthesized via
thermally initiated free-radical polymerization in confines of stainless steel
tubes with dimensions of 100´4,3 mm. In order to compensate for the polymer
shrinkage during the synthesis and prevent the monolith from detachment from
the column wall, the polymerization was conducted under nitrogen pressure. The
excess pressure was varied from 0 bar to 9 bar. The synthesis under pressure
was shown to improve the peak shapes and column efficiency in comparison with
the synthesis in the closed tube. The optimum pressure for poly(DVB-co-EVB-co-HEMA)
monoliths was found to be 3 bar. The efficiency of the column obtained at 3 bar
is 13500 plates/m for propylbenzene (k¢ = 6) and 38300 plates/m for
uracil (k¢ = 0).
Copyright (C) Chemistry Dept., Moscow State University, 2002
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