Screening for metal ligands by liquid chromatography–ligand-exchange–electrospray mass spectrometry

• Published in: Journal of Chromatography A Vol. 1093; no. 1; pp. 36 - 46
• Main Authors: Krabbe, J.G., Lingeman, H., Niessen, W.M.A., Irth, H.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 04.11.2005; Elsevier
• Subjects: Analytical chemistry; Chemistry; Chromatographic methods and physical methods associated with chromatography; Chromatography, Liquid - methods; Exact sciences and technology; Ligand-exchange; Ligands; Liquid chromatography; Mass spectrometry; Metal ligands; Metals - analysis; Other chromatographic methods; Screening; Spectrometry, Mass, Electrospray Ionization - methods; Screening; Metal ligands; Liquid chromatography; Ligand-exchange; Mass spectrometry; Ligand-exchange; Screening; Liquid chromatography; Divalent metal Complexes; Ligand substitution; Zinc II Complexes; Coupled method; HPLC chromatography; Organic ligand; Selectivity; Transition metal Complexes; Electrospray; Postcolumn; Pyridine derivatives; Copper II Complexes; Benzimidazole; Nicotinamide; Continuous flow method
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2005.07.022

Electrospray ionization mass spectrometry is applied for the selective detection of metal ligands after a post-column continuous-flow ligand-exchange reaction. The detection is based on the specific release of a reporter ligand from a metal–reporter ligand complex by a high affinity ligand. Constant infusion and direct-injection experiments are performed to optimize the method. The on-line coupling of a liquid chromatographic separation prior to the continuous flow ligand-exchange reaction enables the screening for high affinity ligands in complex samples. The feasibility of the method is demonstrated by using several ligands with a different affinity for either Cu(II) or Zn(II) ions. The selectivity of the ligand-exchange detection method can be tuned by the choice of the reporter ligand. This is demonstrated by using either 2,2′-bipyridyl or 5-methyl-1,10-phenanthroline as reporter ligands.