【摘要】 在微酸性介质中,铁(Ⅱ)与过氧化氢反应产生的羟基自由基可氧化亮绿SF,使其在吸收峰632nm处的吸光度降低。此反应的最佳条件:①反应时间为20min;②溶液的pH为3.0;③铁(Ⅱ)的初始浓度为100μmol·L-1;④反应温度为25℃。过氧化氢的浓度在50μmol·L-1以内与其吸光度的降低值(ΔA)呈线性关系,检出限(3s/k)为0.25μmol·L-1。据此提出了水发产品浸泡液中残留的痕量过氧化氢的光度测定法。方法用于3个水发产品浸泡液样品的分析,加标回收率在91.0%~112%之间,测定值的相对标准偏差(n=5)在1.9%~2.5%之间。更多还原

【Abstract】 In a slightly acidic medium,brilliant green SF was oxidized by of·OH free radical produced by the reaction between H2O2and Fe(Ⅱ),leading to decrease in absorbance at its absorption maximum of 632nm. Optimum conditions for the reaction were found as follows:① time of reaction:20 min;② acidity of reaction medium:pH 3.0;③initial concentration of Fe(Ⅱ):100μmol·L-1;④ temperature for the reaction:25 ℃. Linear relationship between values of decrease in absorbance(ΔA)and concentration of H2O2 was kept in the range within 50μmol·L-1 with detection limit(3s/k)of 0.25μmol·L-1.On this base,aphotometric method for determination of traces of H2O2remained in the soaking solution of waterscaked foodstuffs was proposed.Three portions of soaking solutions were analyzed by the proposed method and recovery was tested by standard addition method.Values of recovery found were in the range of 91.0%-112%,with RSD′s(n=5)ranged from 1.9%to 2.5%.更多还原