Synthesis and characterization of poly(tetrafluoroethyleneperoxides)

Tetrafluoroethylene (TFE) and oxygen react at low temperature in radical conditions to give perfluoropolyether-polyperoxide polymers. This oxypolymerization reaction has been applied on industrial scale for the manufacture of perfluoropolyethers, presently used in many application fields.It is known that highly unstable polymers containing large amounts of peroxidic units -CF₂CF₂OO- can be formed in particular conditions and may represent a potential hazard in the TFE oxypolymerization process. However little has been reported in the literature on the reaction conditions and the characterization of these polymers.In the present paper we describe the synthesis of perfluoropolyether-polyperoxide polymers with high peroxide content up to the nearly pure poly(perfluoroethyleneperoxide). The investigation is particularly focused to elucidate the relationship between reaction conditions, kinetics and polymer structure. The experimental results indicate that the physical chemical properties of these materials are strongly affected by the peroxide content, this latter depending on the reaction conditions, mainly TFE concentration and initiation rate.     

Kinetics of oxidation of hydrogen peroxide at hemin-modified electrodes in nonaqueous solvents

Hemin adsorbed on graphite electrodes and used to catalyse the reduction of hydrogen peroxide in an aqueous buffer and in a range of nonaqueous solvents has been described. The immobilised hemin is stable in the solvents examined. The rate limiting step involves the reaction between hemin and hydrogen peroxide. Kinetic analysis of the response in nonaqueous solvents showed that I_max / K_m^app increased linearly with the solvent hydrophobicity (log P) in all solvents, a trend that is explained by preferable partitioning of hydrogen peroxide into the polar hemin layer.     

Review: Advances in the Determination of Peroxides by Optical and Spectroscopic Methods

This review focuses on the recent advances made in the field of organic peroxide analysis using spectroscopic methods. In this area, optical techniques and mass spectroscopy play a dominant role. Emphasis has been given to peroxides of great practical significance, such as lipid hydroperoxides, antimalarial peroxides, peroxide-based explosives, and industrially relevant peroxides. The discussion includes current challenges and trends in each of these groups. The underlying chemical principles of the described methods are briefly discussed. All the advances are categorized by branches of spectroscopy, and example applications are outlined. The scope of this paper is restricted to the most significant advances published between 2003 and mid-2013.     

琼脂糖膜固载肌红蛋白催化还原过氧化物的研究

用琼脂糖(agarose)将肌红蛋白(Mb)固定在玻碳电极(GCE)表面,制备了Mb-Agarose膜修饰电极。在水-乙醇混合溶液中,包埋在Agarose中的Mb与电极发生直接电子传递,并且能催化还原H2O2、过氧化丁酮、氢过氧化叔丁基、氢过氧化异丙基苯等过氧化物和NO。Mb-Agarose膜修饰电极具有较好的稳定性和重现性,可用于上述过氧化物和亚硝酸盐的定量检测。     

催化动力学光度法测定痕量铜

在醋酸 -醋酸钠缓冲介质中 ,过氧化氢可缓慢地氧化灿烂甲酚蓝 ,痕量铜离子可强烈地催化此褪色反应。从而建立了动力学光度测定痕量铜的新方法。方法的检出限为 6 .7× 10 -9g/ m L,测定铜的线性范围为0 .0 5— 1.0 μg/ m L。用于茶叶和自来水中痕量铜的分析 ,结果令人满意。     

高效液相色谱-紫外检测法测定食品中的过氧化氢

通过在60℃下超声提取,用亚铁氰化钾和乙酸锌沉淀蛋白质,通过0.45μm滤膜净化样品。利用水和乙腈在200nm波长紫外吸收弱的特点,降低基线噪音。在0.5mL/min流速下,色谱柱对过氧化氢的保留增大,可以与杂质较好分离。用反相高效液相色谱-紫外检测色谱法,在C18柱上不经过衍生化测定了食品中过氧化氢的残留。过氧化氢的检出限为1.5×10^-7mol/L。对实际样品进行检测时,平均回收率R≥75%,RSD≤3%。