| 1. |
- Hemström, Petrus, et al.
(author)
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Atom-transfer radical graft polymerization initiated directly from silica applied to functionalization of stationary phases for high-performance liquid chromatography in the hydrophilic interaction chromatography mode.
- 2006
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In: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 78:20, s. 7098-7103
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Journal article (peer-reviewed)abstract
- Initiation of atom-transfer radical polymerization of a number of monomers (styrene, methyl acrylate, 3-[N,N-dimethyl-N-(methacryloyloxyethyl)ammonium] propanesulfonate, butyl methacrylate, 2,3-epoxypropyl methacrylate) directly from chlorinated porous silica particles has been performed. The grafting has been confirmed and evaluated by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. This initiation technique results in a hydrolytically stable initial Si-C bond, tethering the polymer to the silica substrate. The resulting grafted particles have been used as separation materials for both reversed-phase and hydrophilic interaction chromatography.
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| 2. |
- Hemström, Petrus, et al.
(author)
-
Hydrophilic interaction chromatography
- 2006
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In: Journal of Separation Science. - : Wiley. - 1615-9306 .- 1615-9314. ; 29, s. 1784-1821
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Journal article (peer-reviewed)abstract
- Separation of polar compounds on polar stationary phases with partly aqueous eluents is by no means a new separation mode in LC. The first HPLC applications were published more than 30 years ago, and were for a long time mostly confined to carbohydrate analysis. In the early 1990s new phases started to emerge, and the practice was given a name, hydrophilic interaction chromatography (HILIC). Although the use of this separation mode has been relatively limited, we have seen a sudden increase in popularity over the last few years, promoted by the need to analyze polar compounds in increasingly complex mixtures. Another reason for the increase in popularity is the widespread use of MS coupled to LC. The partly aqueous eluents high in ACN with a limited need of adding salt is almost ideal for ESI. The applications now encompass most categories of polar compounds, charged as well as uncharged, although HILIC is particularly well suited for solutes lacking charge where coulombic interactions cannot be used to mediate retention. The review attempts to summarize the ongoing discussion on the separation mechanism and gives an overview of the stationary phases used and the applications addressed with this separation mode in LC.
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| 3. |
- Hemström, Petrus, et al.
(author)
-
Polymer-based monolithic microcolumns for hydrophobic interaction chromatography of proteins.
- 2006
-
In: Journal of Separation Science. - : Wiley. - 1615-9306 .- 1615-9314. ; 29:1, s. 25-32
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Journal article (peer-reviewed)abstract
- Monolithic capillary columns for hydrophobic interaction chromatography (HIC) have been prepared by thermally initiated, single-step in situ polymerization of mixtures of monovinyl monomers including butyl methacrylate and/or 2-hydroxyethyl methacrylate, with a divinyl crosslinker glycerol dimethacrylate or 1,4-butanediol dimethacrylate using two different porogen systems. Two porogenic solvent mixtures were used; one "hydrophilic", consisting of water, butanediol, and propanol, and one "hydrophobic," comprising dodecanol and cyclohexanol. The porous structures of the monoliths were characterized and their performance was demonstrated with a separation of a mixture of myoglobin, ribonuclease A, and lysozyme under conditions typical of HIC.
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