Improving the detection limit in capillary isotachophoresis using asymmetric neutralisation reaction boundary.

An online method involving transient electrokinetic dosing and ITP with neutralization reaction boundary (NRB) and/or carrier ampholyte-free isoelectric focusing (CAF IEF) was developed for the preconcentration, preseparation, and analytical determination of glyphosate in aqueous samples containing low concentrations of the analyte of interest. Various parameters were investigated in the framework of an optimization study with the aim of achieving the maximum concentration limit of detection (cLOD) decrease in minimum time. The proposed method used CAF IEF and/or ITP with NRB.

Focusing of alkali earth metals in ligand step gradient.

A capillary electroseparation technique for focusing and selective pre-concentration of metal chelates with subsequent on-line isotachophoresis (ITP) analysis was developed and verified. The ions of alkali earth metals (Mg, Ca, Sr, and Ba) were pre-concentrated from the mixture and analyzed. The focusing of the metals was carried out in a ligand step gradient, which was created by the addition of a convenient ligand agent to the regular stationary pH step gradient.

Analysis of amino acids by combination of carrier ampholyte-free IEF with ITP.

The use of carrier ampholyte-free IEF (CAF-IEF) with ITP mobilization and conductivity detection in ITP mode for preconcentration and analysis of amino acids is demonstrated. The analytical procedure consists of three subsequent steps. In the first step, amino acids are continuously dosed from an infinite volume reservoir by electromigration to the column, where a sharp, stationary neutralization reaction boundary (NRB) is created in between acidic and basic primary electrolyte.

Detection system for electro-separation analytical methods.

The paper provides information about the on-line monitoring of components analysed by capillary electrophoresis. For this purposes we developed a whole-capillary transverse scanning detection system, which helps to improve and control the separation processes. A picture from a colour line scanner was used as a source of basic information for autonomous control of the separation process by regulation of the high voltage source.