三种化合物对石棉催化过氧化氢产生羟基自由基的抑制作用

Inhibitory effects of three compounds on chrysotile-catalyzed prodution of ·OH from H_2O_2

为了探讨用柠檬酸铝、混合稀土或亚硒酸钠预处理温石棉对温石棉催化过氧化氢(H2O2)产生羟基自由基(.OH)的影响,用不同浓度的柠檬酸铝、混合稀土或亚硒酸钠溶液浸泡温石棉1小时后,再将其加入到过氧化氢溶液中,利用ESP-300型波谱仪测定反应体中羟基自由基信号。结果显示,温石棉可催化过氧化氢产生羟基自由基,并且所产生的自由基信号(峰高)随石棉浓度升高而增强,呈一定的剂量依赖性。用三种化合物预处理石棉后,其催化过氧化氢产生的自由基信号均减弱,而且其抑制作用随化合物浓度的升高而增强。上述结果表明,用三种化合物预处理温石棉,均可抑制温石棉催化过氧化氢产生羟基自由基。

In order to study the effects of native chrysotile and compounds-pretreated chrysotile on the prodution of ·OH from H2O2, after being soaked in aluminium citrate, mixed rare earths or sodium selenite solutions at different concentrations for 1 hour, native chrysotile or pretreated chrysotile were added to H2O2 solution, then the levels of signal of ·OH were determined using ESR. The results showed that the levels of signal of ·OH were 28, 32, 37, 50 mm respectively when H2O2 were exposed to native chrysotile at 0.125, 0.25, 0.5, 1.0μg/ml respectively, and showed a good dose-effect relationship. But lower levels of signal of ·OH could be found when H2O2 were exposed to compounds-pretreated chrysotile. The results indicated that chrysotile can induce the prodution of ·OH from H2O2, while the pretreatment of chrysotile with aluminium citrate, mixed rare earths or sodium selenite solutions can inhibit chrysotile-induced prodution of ·OH from H2O2.