活性氧介导的四环素类化学发光新方法的建立及其机理研究
发布时间：2018-11-02 16:40
【摘要】：抗生素是最大的一类药品和个人护理产品(PPCPs)中的一种,近年来受到了越来越多的科研关注。在医疗领域用于保护人类和动物健康的PPCPs,已经在环境和食品产业中导致不良累积。抗生素抗药性日益严重并且广泛威胁人类健康。而四环素类抗生素(TCAs)正是其中之一。考虑到TCAs对食品和生态的风险,需要开发灵敏的、有选择性的分析方法,以确保食品安全和消费者的信心。(1)本文提出了Ce(Ⅳ)-Tween 80体系与5种四环素发生化学发光现象的机理。通过紫外光谱和单线态氧(1O2)探针——2-甲基-6-(4-甲氧基苯基)-3,7-二氢咪唑并[1,2-a]-吡嗪-3-酮盐酸盐(MCLA),详细研究了四环素在该体系中的作用。TCAs在表面活性剂Tween中被Ce(Ⅳ)氧化,导致TCAs有机骨架断裂和过氧乙酸的分解,产生单线态氧(1O2)。这一发现在该文中首次报道。此外,叠氮化钠试验和化学发光光谱结果表明,化学发光光谱的最大发射波长约为480nm,分别由Ce(Ⅳ)直接氧化TCAs和Ce(Ⅳ)与Tween 80反应产生的单线态氧(1O2)二聚体产生的。进一步,反应在厌氧条件下进行,发光信号强度变化不大,这表明反应溶液中的溶解氧对该体系没有影响。我们在最优条件下,研究了Ce(Ⅳ)-Tween 80-TCAs化学发光体系的分析特性和参数。并将该方法成功应用于牛奶中四环素类的测定。(2)一种基于甲氧基化的甲壳虫动物荧光素类似物(MCLA)和Ce(Ⅳ)的新型化学发光体系,对5种TCAs表现出超强的化学发光现象。我们发现10 pmol的金霉素(CTC)能增强MCLA-Ce(Ⅳ)体系的化学发光强度30多倍。通过化学发光光谱、自由基捕获剂和紫外光谱研究了MCLA-Ce(Ⅳ)-TCAs体系的化学发光机制。结果表明,Ce(Ⅳ)与TCAs反应产生的单线态氧增强了化学发光。该化学发光体系采用流动注射分析,检测5种TCAs,线性范围为100fmol-20 pmol(r0.999),检出限为20-50 fmol(S/N=3)。该方法检测TCAs的灵敏度与UPLC-MS/MS做了相应的比较。(3)最后,我们建立了一种新颖的、灵敏度高、操作简单、成本低廉的化学发光方法检测TCAs。当高碘酸钠(Na IO4)在碳酸氢钠(NaHCO3)介质中与过氧化氢(H2O2)反应,我们能观察到一个超微弱的化学发光信号,但额外加入50 pmol的甲烯土霉素(MTC)后,发光强度被增大了30倍。Na IO4-NaHCO3-H2O2-TCAs体系的发光机理通过化学发光光谱、自由基捕获剂、电子自旋共振(ESR)和LC-MS/MS研究。结果发现NaIO4-NaHCO3-H2O2-TCAs体系会产生羟自由基(·OH)和超氧自由基(·O2-)。与金霉素(CTC)和4-差向金霉素(4-ECTC)的氧化还原途径不同,其他几种TCAs与羟自由基作用诱导产生强烈的化学发光,羟基化的TCAs是各自的发光体。本文提出了一种新的检测牛奶和蜂蜜中TCAs的方法,检出限为90 fmol(S/N=3)。该法不仅灵敏度高,特异性好,而且对TCAs的氧化过程提供了新的见解。
[Abstract]:Antibiotics are one of the largest class of drugs and personal care products (PPCPs), which have attracted more and more attention in recent years. PPCPs, which is used to protect human and animal health in health care, has led to an accumulation of adverse effects in the environment and the food industry. Antibiotic resistance is becoming increasingly serious and a widespread threat to human health. Tetracycline antibiotic (TCAs) is one of them. Considering the food and ecological risks of TCAs, sensitive and selective analytical methods need to be developed, In order to ensure food safety and consumer confidence. (1) the mechanism of chemiluminescence of Ce (鈪，
本文编号：2306361
[Abstract]:Antibiotics are one of the largest class of drugs and personal care products (PPCPs), which have attracted more and more attention in recent years. PPCPs, which is used to protect human and animal health in health care, has led to an accumulation of adverse effects in the environment and the food industry. Antibiotic resistance is becoming increasingly serious and a widespread threat to human health. Tetracycline antibiotic (TCAs) is one of them. Considering the food and ecological risks of TCAs, sensitive and selective analytical methods need to be developed, In order to ensure food safety and consumer confidence. (1) the mechanism of chemiluminescence of Ce (鈪，
本文编号：2306361
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