Lin J M, Yamada M
Department of Applied Chemistry, Graduate School of Engineering, Tokyo Metropolitan University, 1-1 Minami-Ohsawa, Hachioji, Tokyo 192-0397, Japan.
Anal Chem. 1999 May 1;71(9):1760-6. doi: 10.1021/ac981341m.
The oxidation reaction between periodate and polyhydroxyl compounds was studied. A strong chemiluminescent (CL) emission was observed when the reaction took place in a strong alkaline solution without any special CL reagent. However, in acidic or neutral solution, it was hard to record the CL with our instrument. It was interesting to find that in the presence of carbonate the CL signal was enhanced significantly. When O(2) gas and N(2) gas were blown into the reagent solutions, both background and CL signals of the sample were enhanced by O(2) and decreased by N(2). The spectral distribution of the CL emission showed two main bands (λ = 436-446 and 471-478 nm). Based on the studies of the spectra of CL, fluorescence and UV-visible, a possible CL mechanism was proposed. In strongly alkaline solution, periodate reacts with the dissolved oxygen to produce superoxide radical ions. A microamount of singlet oxygen ((1)O(2)) could be produced from the superoxide radicals. A part of the superoxide radicals acts on carbonates and/or bicarbonates leading to the generation of carbonate radicals. Recombination of carbonate radicals may generate excited triplet dimers of two CO(2) molecules ((CO(2))(2)). Mixing of periodate with carbonate generated were very few (1)O(2)* and (CO(2))(2). These two emitters contribute to the CL background. The addition of polyhydroxyl compounds or H(2)O(2) caused enhancement of the CL signal. It may be due to the production of (1)O(2) during the oxidized decomposition of the analytes in periodate solution. This reaction system has been established as a flow injection analysis for H(2)O(2), pyrogallol, and α-thioglycerol and their detection limits were 5 × 10(-)(9), 5 × 10(-)(9), and 1 × 10(-)(8) M, respectively. Considering the effective reaction ions, IO(4)(-), CO(3)(2)(-), and OH(-) could be immobilized on a strongly basic anion-exchange resin. A highly sensitive flow CL sensor for H(2)O(2), pyrogallol, and α-thioglycerol was also prepared.
研究了高碘酸盐与多羟基化合物之间的氧化反应。当反应在强碱性溶液中进行且无需任何特殊化学发光（CL）试剂时，观察到强烈的化学发光发射。然而，在酸性或中性溶液中，用我们的仪器很难记录到化学发光。有趣的是，发现存在碳酸盐时，化学发光信号显著增强。当向试剂溶液中通入O₂气体和N₂气体时，样品的背景信号和化学发光信号均因O₂而增强，因N₂而减弱。化学发光发射的光谱分布显示出两个主要波段（λ = 436 - 446和471 - 478 nm）。基于对化学发光、荧光和紫外 - 可见光谱的研究，提出了一种可能的化学发光机制。在强碱性溶液中，高碘酸盐与溶解氧反应生成超氧自由基离子。超氧自由基可产生微量的单线态氧（¹O₂*）。一部分超氧自由基作用于碳酸盐和/或碳酸氢盐，导致碳酸根自由基的产生。碳酸根自由基的重组可能产生两个CO₂分子的激发三重态二聚体（(CO₂)₂*）。高碘酸盐与碳酸盐反应生成的¹O₂和(CO₂)₂很少。这两种发射体构成了化学发光背景。加入多羟基化合物或H₂O₂会使化学发光信号增强。这可能是由于在高碘酸盐溶液中分析物氧化分解过程中产生了¹O₂*。该反应体系已被建立用于H₂O₂、邻苯三酚和α - 硫代甘油的流动注射分析，其检测限分别为5×10⁻⁹、5×10⁻⁹和1×10⁻⁸ M。考虑到有效的反应离子，IO₄⁻、CO₃²⁻和OH⁻可固定在强碱性阴离子交换树脂上。还制备了用于H₂O₂、邻苯三酚和α - 硫代甘油的高灵敏度流动化学发光传感器。
