高碘酸钾氧化中性红褪色催化动力学光度法测定痕量硒(Ⅳ)

Study on the kinetic spectrophotometric determination of selenium (Ⅳ) based on oxidation of neutral red with potassium periodate and its application

基于3.2×10-4mol/LH2SO4介质中,痕量硒(Ⅳ)催化KIO4氧化中性红的褪色反应,建立了测定痕量硒(Ⅳ)的动力学光度法。在固定加热时间段(6min)后,于530nm处测定中性红的吸光度降低值监控反应速率。方法检出限为0.36μg/L,校准曲线的质量浓度线性范围为0～8.0μg/L。实验了酸度、反应物浓度、温度、反应时间、干扰离子等因素的影响。研究了反应的最佳条件,并测定了一些动力学参数,催化反应的表观活化能为81.60kJ/mol。11次重复测定0.1μg/25mL和0.2μg/25mLSe(Ⅳ)的相对标准偏差分别为2.1%和1.9%。方法用于食品和人发样品中痕量硒(Ⅳ)的测定,相对标准偏差为0.33%～3.8%,加标回收率为96.0%～103.0%。

Based on the oxidation of neutral red by KIO4 in 3.2×10-4 mol/L sulfuric acid solution,a simple kinetic spectrophotometric method was developed for the determination of trace amounts of Se(Ⅳ).The reaction was monitored spectrophotometrically by measuring the decrease in the absorbance of neutral red at 530 nm with a fixed-time method.The decrease in the absorbance of neutral red is proportional to the concentration of Se(Ⅳ) in the range 0～8.0 μg/L with a fixed time of 4～6 min from the initiation of the reac...