Efficient computerized data acquisition and evaluation for capillary isotachophoresis in quiescent and flowing solution with single detectors placed towards the capillary end

Modeling of the Impact of Ionic Strength on the Electroosmotic Flow in Capillary Electrophoresis with Uniform and Discontinuous Buffer Systems

“…The data of Figure D reveal two aspects, the gradual attainment of a stationary steady state for salicylate 6,30 and the nonconstant net transport of procaine and salicylate through the column. The latter fact underlines that quantitation based on zone length measurements cannot be a reliable approach when a single, stationary on-column detector is employed. ,, …”

“…In the past few years, instrumentation for electrokinetic separations in open-tubular fused-silica capillaries of very small inner diameter (25−75 μm) became available, and papers reporting its use for capillary zone electrophoresis (CZE), capillary isotachophoresis (CITP), and capillary isoelectric focusing (CIEF) appeared in the literature. − A tangentially applied electric field exerts an electric force on charged molecules and, concomitant to electrophoretic migration, induces a transport of the entire solution (referred to as electroosmosis) that is dependent on the characteristics of the capillary surface, the conducting medium, and the applied electric field. The longitudinal electroosmotic flow established in these capillaries was found not to disturb electrophoretic zone formation in CZE, CITP, and CIEF and, with a sensor placed toward one column end and sample application at the other, was determined to allow the detection of cations and anions in a single run in CZE and CITP and the displacement of focusing pattterns across the point of detection in CIEF. , Having discontinuous buffer systems, electroosmosis and thus the net solute transport along the capillary column may change during detection and/or be dependent on sample composition; both of these aspects make quantitation of solutes a challenge when a single detector at a fixed position is employed. − Thus, there is strong interest in knowing the dynamics of the net electrokinetic transport of solutes through the capillary.…”

Stump-like mathematical model and computer simulation on dynamic separation of capillary zone electrophoresis with different sample injections

“…In 1992, Heinrich et al [7] developed a versatile model and computer program for the rapid optimization of ITP (as well as CZE and continuous flow electrophoresis) conditions, such as buffer, ionic strength, temperature, Joule heat, activity coefficients and concentration, etc. Caslavska et al [8] in 1993 performed a simple simulation of ITP evaluation using a commercial, inexpensive, computerized data acquisition system. In 1995, Schafer-Nielsen [9] advanced the time-based simulation of ITP with free definition on boundary conditions for handling n constituents with n pK-values and calculating constituent concentrations and derived parameters as a function of time.…”