Study of flow profile distortions and efficiency in counter pressure moderated partial filling micellar electrokinetic chromatography in relation to the relative buffer zone lengths

Michalke, Daniela; Welsch, Thomas

doi:10.1016/s0021-9673(01)01394-2

Cited by 6 publications

(4 citation statements)

References 34 publications

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“…The leading edge of the flow profile is less disturbed by the introduction of the hydrodynamic flow than either the center of gravity or trailing edge. This observation agrees well with the observations in the literature [10,13]. As expected, when siphoning takes place in the same direction as EOF, the net flow is faster while the flow is slower when the siphoning opposes the EOF.…”

Section: Resultssupporting

confidence: 93%

“…By suppressing flow in discrete regions of the capillary surface of a single capillary, researchers found that the plug flow was perturbed and, in fact, the flow profiles had complimentary shapes in areas with suppressed flow relative to unsuppressed regions of the capillary [9]. This finding is confirmed for partial filling MEKC [10] and explained by theory [11,12]. Tallarek et al [13] studied both EOF and pressure-driven flow in both open and packed CE capillaries and verified that purely electrokinetic driven separations were superior to those that employed pressurized flow.…”

Section: Introductionmentioning

confidence: 85%

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Detecting deviations from pure EOF during CE separations

O'Grady¹,

Noonan²,

McDonnell³

et al. 2007

Electrophoresis

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CE separations are known for their high separation efficiencies. In systems with EOF, the high efficiencies benefit from the flat, plug profile that is characteristic of EOF. When a velocity gradient is present, such as in separations which have nonuniform buffer ionic strength, surface adsorption or differences in the height of the ends of the capillary, a parabolic flow component is introduced. This deviation from purely EOF yields increased peak dispersion and a subsequent decrease in separation performance. This work details a rapid method for detecting deviations from ideal plug flow during the course of a separation using the radially averaged flow profile of a photobleached fluorophore added to the BGE. By comparing the ratio of two different data analysis procedures, deviations from ideal plug flow can be detected. This method allows rapid measurement of flow character and does not interfere with the concurrent separation. We demonstrate easy detection of the onset of hydrodynamic flow induced by both gravity siphoning and an ionic strength buffer discontinuity. A brief analysis of the radially averaged peak shapes is also presented.

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Section: Resultssupporting

confidence: 93%

Section: Introductionmentioning

confidence: 85%

Detecting deviations from pure EOF during CE separations

O'Grady¹,

Noonan²,

McDonnell³

et al. 2007

Electrophoresis

View full text Add to dashboard Cite

show abstract

“…In the case of differences in the electroosmotic velocity in different segments of the capillary (e.g. partial filling technique) band broadening can result from intersegmental pressure [67]. A further source of band broadening can be analyte adsorption at the inner capillary wall, which should be suppressed by a suitable composition of the separation electrolyte or dynamic or static coating of the inner capillary wall.…”

Section: Efficiencymentioning

confidence: 99%

Analysis of Body Fluids by Electrokinetic Chromatographic Techniques

Puignou

Busquets

Galcerán

2006

Electrokinetic Chromatography

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“…The advantage of the pf‐ACE over the ms‐ACE lies in the fact that the ligand does not reach a detector. This can be prerequisite for coupling the separation with a mass spectrometric detection or it significantly contributes to reducing a noise, especially when the ligand is UV‐absorbing [i]. Low consumption of a (possibly expensive, rare) ligand is another big advantage of the pf‐ACE .…”

Section: Introductionmentioning

confidence: 99%

Into the theory of the partial‐filling affinity capillary electrophoresis and the determination of apparent stability constants of analyte‐ligand complexes

2018

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The partial-filling affinity capillary electrophoresis (pf-ACE) works with a ligand present in a background electrolyte that forms a weak complex with an analyte. In contrast to a more popular mobility-shift affinity capillary electrophoresis, only a short plug of the ligand is introduced into a capillary in the pf-ACE. Both methods can serve for determining apparent stability constants of the formed complexes but this task is hindered in the pf-ACE by the fact that the analyte spends only a part of its migration time in a contact with the ligand. In 1998, Amini and Westerlund published a linearization strategy that allows for extracting an effective mobility of an analyte in the presence of a neutral ligand out of the pf-ACE data. The main purpose of this paper is to show that the original formula is only approximate. We derive a new formula and demonstrate its applicability by means of computer simulations. We further inspect several strategies of data processing in the pf-ACE regarding a risk of an error propagation. This establishes a good practice of determining apparent stability constants of analyte-ligand complexes by means of the pf-ACE.

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Study of flow profile distortions and efficiency in counter pressure moderated partial filling micellar electrokinetic chromatography in relation to the relative buffer zone lengths

Cited by 6 publications

References 34 publications

Detecting deviations from pure EOF during CE separations

Detecting deviations from pure EOF during CE separations

Analysis of Body Fluids by Electrokinetic Chromatographic Techniques

Into the theory of the partial‐filling affinity capillary electrophoresis and the determination of apparent stability constants of analyte‐ligand complexes

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