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首页> 外文期刊>Environmental Science & Technology >Environmentally Persistent Free Radicals (EPFRs)-2. Are Free Hydroxyl Radicals Generated in Aqueous Solutions?
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Environmentally Persistent Free Radicals (EPFRs)-2. Are Free Hydroxyl Radicals Generated in Aqueous Solutions?

机译：环境持久性自由基（EPFR）-2。水溶液中是否生成游离羟基自由基？

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摘要

A chemical spin trap, 5,S-dimethyl-l-pyrroline-N-oxide (DMPO), in conjunction with electron paramagnetic resonance (EPR) spectroscopy was employed to measure the production of hydroxyl radical (·OH) in aqueous suspensions of 5% Cu(II)O/silica (3.9% Cu) particles containing environmentally persistent free radicals (EPFRs) of 2-monochlorophenol (2-MCP). The results indicate: (I) a significant differences in accumulated DMPO-OH adducts between EPFR containing particles and non-EPFR control samples, (2) a strong correlation between the concentration of DMPO-OH adducts and EPFRs per gram of particles, and (3) a slow, constant growth of DMPO-OH concentration over a period of days in solution containing 50 ug/mL EPFRs particles + DMPO (ISO mM)+ reagent balanced by 200 uL phosphate buffered (pH = 7.4) saline. However, failure to form secondary radicals using standard scavengers, such as ethanol, dimethylsulfoxide, sodium formate, and sodium azide, suggests free hydroxyl radicals may not have been generated in solution. This suggests surface-bound, rather than free, hydroxyl radicals were generated by a surface catalyzed-redox cycle involving both the EPFRs and Cu(H)O. Toxicological studies clearly indicate these bound free radicals promote various types of cardiovascular and pulmonary disease normally attributed to unbound free radicals; however, the exact chemical mechanism deserves further study in light of the implication of formation of bound, rather than free, hydroxyl radicals.
机译：化学自旋阱5，S-二甲基-1-吡咯啉-N-氧化物（DMPO）与电子顺磁共振（EPR）光谱结合使用，以测量5的水悬浮液中羟基自由基（·OH）的产生含有2-一氯苯酚（2-MCP）的环境持久性自由基（EPFR）的％Cu（II）O /二氧化硅（3.9％Cu）颗粒。结果表明：（I）含EPFR的颗粒与非EPFR对照样品之间积累的DMPO-OH加合物之间存在显着差异；（2）DMPO-OH加合物的浓度与每克颗粒中的EPFR之间有很强的相关性，并且（ 3）DMPO-OH浓度在含有50 ug / mL EPFRs颗粒+ DMPO（ISO mM）+试剂并经200 uL磷酸盐缓冲液（pH = 7.4）盐水平衡的溶液中，在几天内缓慢，恒定地增长。但是，使用标准的清除剂如乙醇，二甲基亚砜，甲酸钠和叠氮化钠无法形成二级自由基，这表明溶液中可能未生成游离羟基。这表明表面结合而不是自由的羟基自由基是由涉及EPFR和Cu（H）O的表面催化氧化还原循环产生的。毒理学研究清楚地表明，这些结合的自由基会促进通常归因于未结合的自由基的各种类型的心血管疾病和肺部疾病；但是，确切的化学机理值得进一步研究，因为这意味着结合的而不是游离的羟基自由基的形成。

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  • 来源
    《Environmental Science & Technology》 |2011年第21期|p.9232-9239|共8页
  • 作者

    Lavrent Khachatryan; Barry Dellinger;

  • 作者单位

    Louisiana State University, Department of Chemistry, Baton Rouge, Louisiana 70803, United States;

    Louisiana State University, Department of Chemistry, Baton Rouge, Louisiana 70803, United States;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);美国《生物学医学文摘》(MEDLINE);美国《化学文摘》(CA);
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