Direct fluorescence detection of Pb2+ and Cd2+ by high-performance liquid chromatography using 1-(4-aminobenzyl)ethylenediamine-N,N,N′,N′-tetraacetate as a pre-column derivatizing agent

A highly sensitive HPLC with direct fluorescent detection (λex = 235 nm, λem = 355 nm) was developed for Pb2+ and Cd2+ complexes with an aromatic polyaminocarboxylate, 1-(4-aminobenzyl)ethylenediamine-N,N,N′,N′-tetraacetate as a pre-column derivatizing agent. A reversed phase partition column pretreated by a cationic surfactant was employed. Although this ligand forms thermodynamically stable complexes with various metal ions, only peaks of Pb2+ and Cd2+ were detected with the ligand-centered emission in the HPLC due to the emissive activity and kinetic stability in the dissociation reaction. The detection limits obtained were 1.5 × 10−8 and 3.3 × 10−9 mol l−1 for Pb2+ and Cd2+, respectively.