Luminol Chemiluminescence in Unbuffered Solutions with a Cobalt(II)−Ethanolamine Complex Immobilized on Resin as Catalyst and Its Application to Analysis

Chemiluminescence (CL) phenomena of carbonates or bicarbonates of potassium, sodium, or ammonium with hydrogen peroxide in the presence of cobalt sulfate were reported. After cobalt(II) solution was injected into the mixture of carbonate/bicarbonate and hydrogen peroxide, a CL signal was given out briefly. The CL conditions of these systems were optimized. The CL reaction mechanisms were studied experimentally by examining the spectrum emitted by the CL system and the effect of various free radical scavengers on CL emission intensity. The results showed that the maximal emission wavelengths of the CO 3 2--H 2 O 2 -Co 2+ and HCO 3 --H 2 O 2 -Co 2+ systems were 440 and 490 nm, respectively. As a result, a radical scavenger of ascorbic acid, thiourea, and superoxide dismutase exhibited different effects on these CL systems. The different CL mechanisms involving the carbon dioxide dimer and the oxygen dimer were revealed, respectively.

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“…The generally accepted mechanism of CL reactions in the presence of Co 2+ was Co 2+ acting as a catalyst. 1,[20][21][22][23][24][25] …”

Section: Effects Of the Concentrations Of Chemicalsmentioning

confidence: 99%

Experimental Studies on the Chemiluminescence Reaction Mechanism of Carbonate/Bicarbonate and Hydrogen Peroxide in the Presence of Cobalt(II)

et al. 2008

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“…The superoxide anion radical produced from the chemical reactions can reduce the yellow dye (NBT) to its blue diformazan pigment, which is only slightly soluble in an aqueous solution and rapidly precipitates. The rate constant for the reduction of NBT by a superoxide is about 5 × 10 4 L/(mol·s) (Lin et al, 2001;Yamakoshi et al, 2003). During the electrolysis procession with bubbling oxygen, the color change of NBT solution at the cathode chamber from yellow to blue was very evident, but at the anode chamber the color of the solution was from yellow to colorless.…”

Section: Confirmation Of Radicals On Cathode Area By Uv-vis Absorptiomentioning

confidence: 99%

Study on superoxide and hydroxyl radicals generated in indirect electrochemical oxidation by chemiluminescence and UV-Visible spectra

Zhang

Zhao

Lin

2008

Journal of Environmental Sciences

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The generation and transformation of radicals on the cathode of indirect electrochemical oxidation were studied by chemiluminescence (CL) and UV-Visible spectra in the reactor with a salt bridge that connected the separated chambers. The CL intensity of 4 × 10 −9 mol/L luminol on the cathode with bubbling oxygen was about seven times that of the intensity without it, which was because of the generation of reactive oxygen species (ROS). The existence of ROS, especially the generation of the superoxide radical, could be affirmed by the fact that the CL intensity of 4 × 10 −9 mol/L 2-methyl-6-(4-methoxyphenyl)-3,7-dihydroimidazo[1,2-a]pyrazin-3-one with bubbling oxygen was about four times that of the intensity without it. However, there was no chemiluminescence on the anode under the same condition. The change in the UV-Visible spectra of nitro blue tetrazolium and N,N-dimethyl-4-nitrosoaniline at the cathode chamber affirmed the transformation from oxygen to superoxide and hydroxyl radicals. The mechanism of the superoxide and hydroxyl radical generation and transformation on the cathode was discussed with the help of the experimental results and relative references.

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“…Chemiluminescence (CL) is a powerful analytical technique that has excellent sensitivity, wide linear dynamic range and requires relatively simple and inexpensive instrumentation [8,9]. To our knowledge, there were a few reports for the determination of folic acid based on CL analysis system [10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Determination of folic acid by chemiluminescence based on peroxomonosulfate-cobalt(II) system

Zhang

Zhao

Lin

2008

Talanta

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119

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Based on the chemiluminescence (CL) phenomena of folic acid in peroxomonosulfate-cobalt(II) system, a rapid and sensitive CL method was developed for determination of folic acid in pharmaceutical preparations and its urinary metabolism processes. Under the optimum conditions, the relative CL intensity was linear over the concentration ranging from 10 −9 to 8 × 10 −7 mol L −1 (R 2 = 0.9991) with a detection limit as low as 6 × 10 −10 mol L −1 (S/N = 3) and relative standard deviation was 2.63% for 2 × 10 −8 mol L −1 folic acid (n = 11). This method has been successfully applied to the determination of folic acid in tablets and human urine. The blank CL emission was yielded owing to the formation of singlet oxygen molecular pair from the quenching experiment of 1,4-diazabicyclo[2.2.2]octane, and pterine-6-carboxylic acid might be the degradation intermediate in this system and it also acts an energy acceptor and sensitizes the chemiluminescence based on the studies of the CL and fluorescence spectra.

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Luminol Chemiluminescence in Unbuffered Solutions with a Cobalt(II)−Ethanolamine Complex Immobilized on Resin as Catalyst and Its Application to Analysis

Cited by 107 publications

References 44 publications

Experimental Studies on the Chemiluminescence Reaction Mechanism of Carbonate/Bicarbonate and Hydrogen Peroxide in the Presence of Cobalt(II)

Experimental Studies on the Chemiluminescence Reaction Mechanism of Carbonate/Bicarbonate and Hydrogen Peroxide in the Presence of Cobalt(II)

Study on superoxide and hydroxyl radicals generated in indirect electrochemical oxidation by chemiluminescence and UV-Visible spectra

Determination of folic acid by chemiluminescence based on peroxomonosulfate-cobalt(II) system

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