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- Dinh, Ngoc Phuoc, 1985-, et al.
(författare)
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Water uptake on polar stationary phases under conditions for hydrophilic interaction chromatography and its relation to solute retention
- 2013
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Ingår i: Journal of Chromatography A. - : Elsevier. - 0021-9673 .- 1873-3778. ; 1320, s. 33-47
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- In hydrophilic interaction chromatography, water is known to accumulate on the stationary phase to form a water enriched layer, which is believed to play an important role in the retention mechanism. To gain a better understanding retention mechanism in HILIC, we have determined the water uptake on twelve different HILIC stationary phases. Non-modified and monomerically functionalized silica phases followed a pattern of monolayer formation followed by multiple layer adsorption, while the water uptake on polymerically functionalized silica stationary phase showed the characteristics of formation and swelling of hydrogels. This difference in the nature of water accumulation was found to be related to different water uptake patterns when methanol and tetrahydrofuran were added to 80:20 % (v/v) acetonitrile/water by replacing 5 % of the acetonitrile as tertiary solvents, and also when ammonium acetate was added as buffering electrolyte. The relationship between water uptake and retention mechanism was investigated by looking at the correlation between retention factors of neutral analytes and phase ratios of HILIC columns, calculated either as surface area (adsorption) or volume of the water layer enriched from the acetonitrile/water eluent (partitioning). Regardless of the adsorption or partitioning mechanism, the interaction of neutral analytes and stationary phase could be mainly the hydrogen bonding between analytes and the accumulated water in the water enriched layer.
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- Fornstedt, T, et al.
(författare)
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Peak tailing and slow mass transfer kinetics in nonlinear chromatography
- 1996
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Ingår i: JOURNAL OF CHROMATOGRAPHY A. - : ELSEVIER SCIENCE BV. - 0021-9673. ; 742:1-2, s. 55-68
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Peak tailing has two main origins in chromatography: (i) heterogenous mass transfer kinetics, (ii) heterogenous thermodynamics with overloading of a nonlinear isotherm. The individual effects of each of these sources and the conditions under which they gi
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| 7. |
- Tong, XM, et al.
(författare)
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Computer simulation of particle separation based on non-equilibrium swelling
- 1999
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Ingår i: JOURNAL OF CHROMATOGRAPHY A. - : ELSEVIER SCIENCE BV. - 0021-9673. ; 831:1, s. 51-62
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Steric/hyperlayer field-flow fractionation (FFF) is an established analytical technique for separating and characterizing particles in the 1-100 mu m diameter range. The separation can be based on differences in size, density, shape and mechanical propert
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