EDTA was used as an enhancer for Fe 2+ catalyzed light emission from luminol oxidation by dissolved oxygen. As a result, the limit of detection for ferrous ion with flow injection analysis was improved by a fact...EDTA was used as an enhancer for Fe 2+ catalyzed light emission from luminol oxidation by dissolved oxygen. As a result, the limit of detection for ferrous ion with flow injection analysis was improved by a factor of 160 by addition of EDTA to the luminol solution. Fe 2+ and Fe 3+ were determined simultaneously with a novel copper-coated zinc reductor minicolumn installed in one of the shunt after sample splitting in the manifold. The reductor minicolumn can be used for 3000 determinations at least. The dynamic range of determination was 1×10 -9 ～1×10 -5 mol·L -1 , with the limit of detection of 2.7×10 10 and 3.5×10 10 mol·L 1 ,for Fe 2+ and Fe 3+ , respectively. The preci sion for determination of 2×10 7 mol·L 1 of Fe 2+ and Fe 3+ was 2.3% and 4.0% (n=8), respectively, at a sampling rate of 60 h -1 . Cr 3+ and Co 2+ interfere. Fe 2+ and Fe 3+ in mixture were determined with satisfactory results. Samples of Fe 2+ and Fe 3+ were determined simultaneously and the results in good agreement with the standard spectrophotometric method. Indications were shown that EDTA functions as an enhancer, Fe 2+ as a catalyst, and oxygen is the oxidant of the chemiluminescent reaction, and the mechanism of the reaction was discussed.展开更多
In this work, the intensification of luminol electrochemiluminescence (ECL) by metallic oxide nanoparticles (MONPs), as ZnO, MnO2,In2O3 and TiO2 , under alkaline condition is reported and the related mechanism is stud...In this work, the intensification of luminol electrochemiluminescence (ECL) by metallic oxide nanoparticles (MONPs), as ZnO, MnO2,In2O3 and TiO2 , under alkaline condition is reported and the related mechanism is studied. It is found that all four types of those MONPs exhibit the effect toward the ECL intensification of luminol. Furthermore, the silica sol-gel film is taken to immobilize the MONPs onto the platinum electrodes. The so-obtained modified electrodes also show the enhanced ECL and better signal/noise ratio, as well improved signal stability. Finally, the ECL reagent, luminol, is immobilized together with the MONPs onto the electrode surface to perform as the ECL sensor. On resulting sensors, good linear responses are obtained toward hydrogen peroxide. The mechanism of intensification of luminol ECL by MONPs is discussed in this paper. It is proposed that the ECL intensification can be attributed to the production of reactive oxygen species, as well as the adsorption of luminol on surface of MONPs.展开更多
文摘EDTA was used as an enhancer for Fe 2+ catalyzed light emission from luminol oxidation by dissolved oxygen. As a result, the limit of detection for ferrous ion with flow injection analysis was improved by a factor of 160 by addition of EDTA to the luminol solution. Fe 2+ and Fe 3+ were determined simultaneously with a novel copper-coated zinc reductor minicolumn installed in one of the shunt after sample splitting in the manifold. The reductor minicolumn can be used for 3000 determinations at least. The dynamic range of determination was 1×10 -9 ～1×10 -5 mol·L -1 , with the limit of detection of 2.7×10 10 and 3.5×10 10 mol·L 1 ,for Fe 2+ and Fe 3+ , respectively. The preci sion for determination of 2×10 7 mol·L 1 of Fe 2+ and Fe 3+ was 2.3% and 4.0% (n=8), respectively, at a sampling rate of 60 h -1 . Cr 3+ and Co 2+ interfere. Fe 2+ and Fe 3+ in mixture were determined with satisfactory results. Samples of Fe 2+ and Fe 3+ were determined simultaneously and the results in good agreement with the standard spectrophotometric method. Indications were shown that EDTA functions as an enhancer, Fe 2+ as a catalyst, and oxygen is the oxidant of the chemiluminescent reaction, and the mechanism of the reaction was discussed.
基金supported by the National Natural Science Foundation of China (20275025 & 20675055)the Natural Science Foundation of Jiangsu Province (BK2009111)Technology Plan of Suzhou (SYJG0901)
文摘In this work, the intensification of luminol electrochemiluminescence (ECL) by metallic oxide nanoparticles (MONPs), as ZnO, MnO2,In2O3 and TiO2 , under alkaline condition is reported and the related mechanism is studied. It is found that all four types of those MONPs exhibit the effect toward the ECL intensification of luminol. Furthermore, the silica sol-gel film is taken to immobilize the MONPs onto the platinum electrodes. The so-obtained modified electrodes also show the enhanced ECL and better signal/noise ratio, as well improved signal stability. Finally, the ECL reagent, luminol, is immobilized together with the MONPs onto the electrode surface to perform as the ECL sensor. On resulting sensors, good linear responses are obtained toward hydrogen peroxide. The mechanism of intensification of luminol ECL by MONPs is discussed in this paper. It is proposed that the ECL intensification can be attributed to the production of reactive oxygen species, as well as the adsorption of luminol on surface of MONPs.
