Capillary column coupling isotachoelectrophoresis

This technique has found limited applications to the determination of organic compounds, cations and anions in water. The technique offers many similar advantages to ion chromatography, namely multiple-ion analysis, little or no sample pretreatment, speed, sensitivity and automation. 

Separation capillary columns are made in fluorinated ethylene-propylene copolymer. Detection is achieved by conductivity cells and an 

To satisfy the requirements for the properties of the leading electrolyte applied in the first stage and, consequently, to decide its composition, two facts had to be taken into account the pH value of the leading electrolyte needs to be around four or less and at the same time the separations of the macroconstituents need to be optimised by means other than adjusting the pH of the leading electrolyte (anions of strong acids). 

The choice of the leading electrolyte for the second stage, in which the microconstituents were finally separated and quantitatively evaluated, is straightforward, involving a low concentration of the leading constituent (low detection limit) and a low pH of the leading electrolyte (separation according to pK values). 

Although in some instances it is possible to determine low concentrations of inorganic anions by capillary zone electrophoresis [24], problems arise when the concentrations of the sample constituents vary considerably. This is due to the fact that the determination of microconstituents may require the sample load to have an impact on both the migration velocities and the resolution of analytes [25]. The use of indirect detection, as preferred in the case of inorganic anions [24,26] is also less capable of achieving adequate load capacities. 

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Ion exchange chromatography (Chapter 12) is a well-established technique applicable to the determination of particular types of organic and organometallic compounds and anions and cations as has capillary column coupling isotachoelectrophoresis (Chapter 13). 

Kaniansky et al. [21] have also reported on a method for the determination of nitrate, sulphate, nitrite, fluoride and phosphate by capillary zone electrophoresis coupled with capillary isotachoelectrophoresis in the column coupling configuration. Such distributions of these anions are typical for many environmental matrices, and it is shown that capillary isotachophoresis-capillary zone electrophoresis tandem enables the capillary isotachoelectrophoresis determination of the macroconstituents, while capillary isotachophoresis-preconcentrated microconstituents cleaned up from the... 

Chloride, sulphate Column coupling capillary isotachoelectrophoresis 0.02-0.1 mg L- [22]... 

Chloride, fluoride, nitrate, sulphate, nitrite and phosphate Column coupling capillary isotachoelectrophoresis - sub pg L [23]... 

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