title: Separation and direct UV detection of lanthanides complexed with pyridine-2-carboxylic acid by capillary electrophoresis.
abstract: Separation and detection of lanthanides by capillary zone electrophoresis in the presence of pyridine-2-carboxylic acid (picolinic acid) as UV-absorbing complexing agent were investigated. The resolution of partially complexed positively charged complexes is improved by using two buffer ligands competing with picolinic acid for metal ions. When hydroxyisobutyric acid (HIBA) and formic acid are used together as competing ligands, this provides complete separation of all 14 lanthanides with good peak shapes. An on-column separation of 14 lanthanides was achieved in only 9 min using 0.8 mmol/l picolinic acid, 10 mmol/l HIBA and 25 mmol/l formic acid at pH 4.7. Determination of lanthanide complexes was performed by direct detection at 210 nm. Detection limits (signal-to-noise ratio=3) are ca. 0.53-0.96 microg/ml.
authors.affiliation: Department of Chemistry, Technical University of Istanbul, Turkey.
authors.forename: N
authors.initials: N
authors.lastname: Oztekin
authors.forename: F B
authors.initials: FB
authors.lastname: Erim
mesh_terms: D019075:Electrophoresis, Capillary / Q000379:methods*; D005561:Formates / Q000737:chemistry; D028581:Lanthanoid Series Elements / Q000032:analysis / Q000302:isolation & purification*; D010848:Picolinic Acids / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*
chemical_list: D005561:Formates; D028581:Lanthanoid Series Elements; D010848:Picolinic Acids; C030544:formic acid; C030614:picolinic acid