A chelate complex-enhanced luminol system for selective determination of Co(II), Fe(II) and Cr(III)

作者：Kim Kyung Min; Kim Young Ho; Oh Sang Hyub; Lee Sang Hak^*

来源：Luminescence, 2013, 28(3): 372-377.

DOI：10.1002/bio.2392

• chemiluminescence
• luminol system
• chelating-reagent

A determination method for Co(II), Fe(II) and Cr(III) ions by luminol-H2O2 system using chelating reagents is presented. A metal ion-chelating ligand complex with a Co(II) ion and a chelating reagent like ethylenediaminetetraacetic acid (EDTA) produced highly enhanced chemiluminescence (CL) intensity as well as longer lifetime in the luminol-H2O2 system compared to metals that exist as free ions. Whereas free Cu(II) and Pb(II) ions had a strong catalytic effect on the luminol-H2O2 system, significantly, the complexes of Cu(II) and Pb(II) with chelating reagents lost their catalytic activity due to the chelating reagents acting as masking agents. Based on the observed phenomenon, it was possible to determine Co(II), Fe(II) and Cr(III) ions with enhanced sensitivity and selectivity using the chelating reagents of the luminol-H2O2 system. The effects of ligand, H2O2 concentration, pH, buffer solution and concentrations of chelating reagents on CL intensity of the luminol-H2O2 system were investigated and optimized for the determination of Co(II), Fe(II) and Cr(III) ions. Under optimized conditions, the calibration curve of metal ions was linear over the range of 2.0x10-8 to 2.0x10-5M for Co(II), 1.0x10-7 to 2.0x10-5M for Fe (II) and 2.0x10-7 to 1.0x10-4M for Cr(III). Limits of detection (3 sigma/s) were 1.2x10-8, 4.0x10-8 and 1.2x10-7M for Co(II), Fe(II) and Cr(III), respectively.

• 出版日期2013-6