Development of capillary electrophoresis for the determination of metal ions using mixed partial and complete complexation techniques

• Published in: Journal of Chromatography A Vol. 977; no. 1; pp. 135 - 142
• Main Authors: Naujalis, Evaldas, Padarauskas, Audrius
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.11.2002; Elsevier
• Subjects: Analytical chemistry; Chemistry; Chromatographic methods and physical methods associated with chromatography; Earth, ocean, space; Electrophoresis, Capillary - methods; Exact sciences and technology; External geophysics; Ions; Metal cations; Metals - analysis; Meteorology; Other chromatographic methods; Phenanthroline; Spectrophotometry, Ultraviolet; Water in the atmosphere (humidity, clouds, evaporation, precipitation); Derivatization, electrophoresis; Metal cations; Phenanthroline; Snow; Complexation; Divalent metal Ions; Chemical analysis; Zone electrophoresis; Phase composition; Capillary electrophoresis; Derivatization; Mobile phase; Ultraviolet detector; Transition metal Ions; Complexing agent; pH; Quantitative analysis
• ISSN: 0021-9673
• DOI: 10.1016/S0021-9673(02)01350-X

A new capillary electrophoretic (CE) method was developed for the selective and sensitive determination of common metal ions. The proposed method is based on conventional CE separation of metal cations followed by complete complexation of separated analytes with 1,10-phenanthroline using the zone-passing technique. This approach combines both partial and complete complexation modes and, thus, enables rapid, selective, efficient separation together with sensitive direct UV detection of metal species. The optimal conditions for the separation and derivatization reaction were established by varying type of electrolyte, electrolyte pH, introduction time and concentration of 1,10-phenanthroline. The optimized separations were carried out in 50 mmol l −1 glycolic acid electrolyte (pH 6.0 with imidazole) using direct UV detection at 254 nm. Five common metal cations (Fe 2+, Co 2+, Ni 2+, Cu 2+ and Zn 2+) were separated in less than 4 min. The proposed system was applied to the determination of Fe(II) and Zn(II) in snow samples. The recovery tests established for snow samples were within the range 100±12%.