Factors influencing trace ion analysis with preconcentration by electrostacking

The importance of capillary electrophoresis, capillary electrochromatography, and ion chromatography in separations of inorganic ions

“…The electromigration dispersion predicted in a CuSO 4 system has been confirmed experimentally [4,35]. The reversed elution order of Na 1 and Ca 2+ has been observed which is caused by complexation of Ca 2+ ions with sulfate anions [4,35]. The presence , poly(diallyldimethylammonium) hydroxide; Bis-Tris, bis(2-hydroxyethyl)imino-tris(hydroxymethyl)methane; SAE, strong anion exchanger; SCX, strong cation exchanger …”

Optimization of the electrokinetic sample introduction in capillary electrophoresis for the ultra trace determination of anions on silicon wafer surfaces

“…Taking these results into account, a detection limit (LOD) of approximately 1 ng mL -1 should be attainable. This LOD can be achieved by transient isotachophoretic preconcentration during the electrokinetic sample introduction [10,13]. The disadvantage of the method described is in the use of octanesulfonate, because this cannot be obtained without sulfate contamination.…”

“…For this purpose the wafer surface is completely wetted with a minimum volume of ultrapure water (UPW) necessary to obtain a suitable sample volume. The ultra trace methods described in the literature [9][10][11][12][13] have the disadvantage that octanesulfonate is used for transient isotachophoretic preconcentration during the electrokinetic sample introduction. Octanesulfonate, however, cannot be obtained without sulfate contamination.…”

Electrostacking online sample pre‐concentration capillary electrophoresis with amperometric detection for β2‐agonists in human urine

“…Since these methods were obviously time-consuming and tedious, on-column sample stacking methods have been developed for coupling with CE. As reported in some references, the on-column sample stacking methods such as pH-mediated sample stacking [15], on-column isotachophoresis [16,17], field-amplified [18], large-volume sample stacking [19] and electrostacking [20], have been applied to pre-concentrate the polar analytes which can be loaded into the capillary and improve the analytical sensitivity.…”