Innovative development in isotachophoresis (displacement electrophoresis)

Gebauer, Petr; Caslavska, Jitka; Thormann, Wolfgang

doi:10.1016/0165-022x(91)90057-4

Cited by 11 publications

(3 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the literature, there exist numerous works on numerical modeling of ITP [17][18][19][20]. In 1983, Bier et al [21] proposed a full-scale, unified mathematical model for transient electrophoretic separation processes and presented simulation results for different modes of electrophoresis.…”

Section: Mathematical Model For Itpmentioning

confidence: 99%

A method to determine quasi‐steady state in constant voltage mode isotachophoresis

2011

View full text Add to dashboard Cite

Identification of the steady state is very challenging in isotachophoresis (ITP); especially in complex microgeometries, such as dog-leg channels or cross-channel junctions. In this work, an elastic matching method is applied to determine the quasi-steady state in microscale ITP. In the elastic matching method, the similarity between two profiles is calculated by comparing intensity distribution of two images or profiles. To demonstrate this similarity-based analysis technique for ITP, a constant voltage mode ITP model is developed and applied to a five-component ITP system. Hydrochloric acid and caproic acid are used as the leader and terminator, respectively, while histidine is used as the counter-ion. Two sample components, acetic acid and benzoic acid, are separated under the action of an applied electric field in both straight and dog-leg microchannels. This analysis shows that conductivity profiles provide a better measure to determine the quasi-steady state in an ITP process. For a straight microchannel, the quasi-steady state is achieved in less than a minute with a total potential drop of 100 V in a 2 cm long channel. In a straight channel, a true steady state can be achieved for ITP with appropriate countercurrent flow where stationary zones are formed, but the time it takes to reach the steady state is much longer than the without counter flow case. The numerical results indicate that a steady state cannot be reached in a dog-leg microchannel because of sample dispersion and refocusing at and near the intersections and at the branch channels. However, the elastic matching method can be used to determine the quasi-steady state in a dog-leg microchannel.

show abstract

Section: Mathematical Model For Itpmentioning

confidence: 99%

A method to determine quasi‐steady state in constant voltage mode isotachophoresis

2011

View full text Add to dashboard Cite

show abstract

“…The concentration of each component in its respective zone is (8) where M j is the mass of species j in that zone.…”

Section: Theorymentioning

confidence: 99%

“…ITP is an electrophoretic separation method which utilizes a discontinuous buffer system [7,8] comprised of a leading electrolyte (LE) and trailing electrolyte (TE) having the highest and lowest mobilities, respectively, of all constituents in a target sample. A complex analyte sample is placed between the LE and TE, and some time after current is applied, those analytes with the same charge sign as the leading ion will stack themselves into a "train" of contiguous self-sharpening zones based on their electrophoretic mobilities.…”

Section: Introductionmentioning

confidence: 99%

Prediction of the location of stationary steady‐state zone positions in counterflow isotachophoresis performed under constant voltage in a vortex‐stabilized annular column

Harrison

Ivory²

2007

J of Separation Science

View full text Add to dashboard Cite

A theoretical model is presented and an analytical expression derived to predict the locations of stationary steady-state zone positions in ITP as a function of current for a straight channel under a constant applied voltage. Stationary zones may form in the presence of a countercurrent flow whose average velocity falls between that of a pure leader zone and of a pure trailer zone. A comparison of model predictions with experimental data from an anionic system shows that the model is able to predict the location of protein zones with reasonable accuracy once the ITP stack has formed. This result implies that an UP stack can be precisely directed by the operator to specific positions in a channel whence portions of the stack can be removed or redirected for further processing or analysis.

show abstract

Impact of electroosmosis on isotachophoresis in open‐tubular fused‐silica capillaries: Analysis of the evolution of a stationary steady‐state zone structure by computer simulation and experimental validation

1995

Self Cite

View full text Add to dashboard Cite

A dynamic computer model for simulation of open-tubular capillary electrophoresis that includes in situ calculation of electroosmosis along the fused-silica capillary column has been applied to the characterization of an anionic isotachophoretic system in presence of a cathodic electroosmotic flow. For each column segment, electroosmosis is calculated with the use of a wall mobility, the voltage gradient and the degree of dissociation of the silanol surface groups of the capillary wall. Then, the bulk capillary flow is taken to be the average of all of the segment flows and considered to represent a plug flow. This simple approach enables the combined simulation of the temporal behavior of an isotachophoretic zone structure in presence of electroosmosis. For a model anionic isotachophoretic configuration at pH 6, simulation data reveal the asymptotic formation of a stationary steady-state zone configuration in which electrophoretic and electroosmotic zone displacements are opposite and of equal magnitude. The position of the stationary boundaries are predicted to be dependent on the selected wall pK and mobility values. For two different instruments, qualitative agreement between experimental data and simulation results obtained with a wall pK between 5 and 6 is demonstrated. However, for the two experimental setups, significant differences in electroosmotic pumping (i.e. wall mobility values) are noted.

show abstract

Innovative development in isotachophoresis (displacement electrophoresis)

Cited by 11 publications

References 48 publications

A method to determine quasi‐steady state in constant voltage mode isotachophoresis

A method to determine quasi‐steady state in constant voltage mode isotachophoresis

Prediction of the location of stationary steady‐state zone positions in counterflow isotachophoresis performed under constant voltage in a vortex‐stabilized annular column

Impact of electroosmosis on isotachophoresis in open‐tubular fused‐silica capillaries: Analysis of the evolution of a stationary steady‐state zone structure by computer simulation and experimental validation

Contact Info

Product

Resources

About