[Measurement of binding constants of metal complex by indirect ultraviolet affinity capillary electrophoresis].
The binding constants of complexes formed by metal ions and ligands have been obtained by affinity capillary electrophoresis, according to the measurement of the migration times of metal ions effected by ligands in aqueous media, under the experimental model named electrophoretic peak shifting. This method has been applied to the research of magnesium ion with citric acid and manganese ion with tartaric acid. Under the condition of imidazole and acetate buffer (pH 5.01) at 20 kV running voltage, the migration times of metal ion with ligand of different concentrations have been measured. The estimated logarithmic values of binding constants after computation were 3.27 for magnesium-citric acid and 2.28 for manganese-tartaric acid, which showed that the results were in agreement with the data in previous literature. This method is applicable to the measurement of the binding constants of complex systems with 1:1 ratio.
Xia
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ZN
Institute of Environment and Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China. znxia@cqu.edu.cn
Liu
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Zhang
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Qu
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D002614:Chelating Agents / Q000737:chemistry*; D019343:Citric Acid / Q000032:analysis; D019075:Electrophoresis, Capillary / Q000379:methods*; D007477:Ions; D008024:Ligands; D008274:Magnesium / Q000032:analysis*; D008345:Manganese / Q000032:analysis; D013056:Spectrophotometry, Ultraviolet; D013644:Tartrates / Q000032:analysis
D002614:Chelating Agents; D007477:Ions; D008024:Ligands; D013644:Tartrates; D019343:Citric Acid; D008345:Manganese; D008274:Magnesium; C029768:tartaric acid