Lanthanide luminescence quenching as a detection method in ion chromatography. Chromate in surface and drinking water

Dynamic quenching of Eu(IIl) and TB(III) luminescence by inorganic anions as a detection method in ion chromatography was investigated. To obtain a high luminescence intensity lanthanide(III) complexes are formed with ligands which make indirect excitation of the ions possible. Only a few anions (e.g. nitrite, chromate) induce efficient dynamic luminescence quenching. Chromate is an efficient quencher of TB-acac luminescence. Samples of tap water and surface water spiked with chromate were injected into a high-performance liquid chromatographic system with post-column addition of the luminescent complex. In this way a detection limit of 1.1 · 10-37 M (13 ppb) of chromate could be obtained