Simultaneous Determination of Copper(II) and Cobalt(II) by Ion Chromatography Coupled with Chemiluminescent Detection

Abstract

The pollution of water with transition-metal ions has increased dramatically in recent years as a consequence of the expansion of industrial activities. Transition-metal ions are toxic when their concentrations in water exceed certain levels. Therefore, a rapid and convenient method for their simultaneous analysis in natural water samples has attracted much attention.Ion chromatography (IC) has been successfully used to separate transition metal-ions. The widely used IC methods for determining transition-metal ions are based on a cation or bifunctional exchange separation, followed by post-column complexation with 4-(2-pyridylazo)resorcinol (PAR) to form chelates monitored by spectrophotometric detection.1-7 Some of them show good sensitivity and selectivity. However, a postcolumn reactor between the separator column and the UV-Vis detector is required for the complex, which results in a long reaction time and complicated equipment. 5-7The chemiluminescence (CL) analysis of transition-metal ions in recent years has received increasing attention for its high sensitivity, simple instrumentation, wide dynamic range and good reproducibility. However, CL methods often suffer from low selectivity because many coexisting substances can react with luminol or other CL reagents to give light emission. Therefore, the coupling of the highly sensitive detection of CL with the high-efficiency separation of IC can improve the selectivity of CL detection. The cause limiting its widespread application was the compatibility of IC separation and CL detection. If successful, it would maintain a good separation efficiency of IC, and provide a high sensitivity of CL. To the best of our knowledge, almost all post-column CL assays for trasition-metal ions have been based on a metal-catalyzed reaction of luminol with hydrogen peroxide (H2O2). [8][9][10][11][12] Therefore, it is highly desirable to develop a new CL system in the absence of any special CL reagents for the simultaneous determination of transition-metal ions.The decomposition of H2O2 catalyzed by transition-metal ions or their complexes in homogeneous and heterogeneous systems has been extensively studied, and different mechanisms have been suggested for these reactions. [13][14][15][16][17] It is well known that the decomposition of H2O2 in the presence of transition-metal ions produces singlet oxygen ( 1 O2), which is a light-emitting species. 18 Although the CL emission from the decomposition of H2O2 has been recognized for a long time, and many CL systems using H2O2 as an oxidant have been reported, 19-21 the application of the decomposition of H2O2 catalyzed by transition-metal ions without any special CL reagents is rare. In our previous work, 22 we developed a Cu(II)-H2O2-amino acids system for the direct determination of tryptophan and phenylalanine after liquid-chromatographic separation with water alone as the eluent.In the present work, based on the decomposition of H2O2 catalyzed by transition-metal ions, such as Cu(II) and Co(II), in a basic aqueous solution to...

Simultaneous Speciation of Iron(II) and Iron(III) by Ion Chromatography with Chemiluminescence Detection

“…13 This method is widely used as an analytical tool for many applications, such as analyses of a variety of trace metals and other substances. 7,[14][15][16][17] Numerous analytical techniques have been employed in the determination of heavy and transition metals, but ion chromatography seems to be one of the most effective and simple techniques to determine both anionic and cationic species, owing to its high separation efficiency and selectivity, and probable simultaneous determination of different oxidation states of the same element via flow injection analysis (FIA). The eluent commonly used for this application is oxalic acid or pyridine-2,6-dicarboxylic acid (PDCA).…”

SIMULTANEOUS SPECTROPHOTOMETRIC DETERMINATION OF Cu(II) AND Co(II) USING 5-BROMOSALICYLALDEHYDE THIOSEMICARBAZONE BY PARTIAL LEAST SQUARES REGRESSION METHOD

“…[2][3][4][5][6][7][8][9][10][11] Few reports have been published on the simultaneous determination of Cu(II) and Co(II) in different samples. [12][13][14] Until now, there is no scientific paper in the application of 5-bromosalicylaldehyde thiosemicarbazone (5-BSAM) for simultaneous determination of these ions. In the present work a very rapid, sensitive, selective and low-cost PLS for simultaneous determination of copper and cobalt using 5-BSAT in dimethylformamide (DMF) solvent is described.…”

Comparison of amounts of Cd (II) adsorbed in four vegetable species with using impregnated resin containing mixed ligands; 1,4-diaminoantraquinone and 1,4-dihydroxyantraquinone

“…Low levels of exposure to this element over prolonged periods cause high blood pressure, sterility among males, kidney damage. Therefore, extraction of this ion from water and wastewater, before its discharge into the environment, is very important (Lu et al, 2003).…”