硫酸高铈分光光度法测定过氧化氢的优化研究

Optimization of Spectrophotometric Determination of Hydrogen Peroxide by High Cerium Sulfate

考察了不同pH和反应时间对硫酸高铈与过氧化氢反应后吸光度的影响,得出硫酸高铈分光光度法测定过氧化氢的最优条件:波长316 nm、硫酸高铈浓度0.002 mol·L^(-1)、pH=0.4、反应时间6 min。采用硫酸高铈分光光度法和常用的草酸钛钾分光光度法分别测定50.00 mg·L^(-1)的过氧化氢,前者的相对平均偏差、相对误差、标准偏差和相对标准偏差都明显低于后者。草酸钛钾分光光度法无法测定0~5.00 mg·L^(-1)的低浓度过氧化氢,而硫酸高铈分光光度法在该浓度范围的标准曲线R^(2)=0.9990,检出限为0.11 mg·L^(-1),加标回收率在98.67%~105.00%,相对标准偏差为0.55%,体现出较高的灵敏度、准确度和精密度。

The effects of different pH and reaction time on the absorbance after the reaction of cerium sulfate with hydrogen peroxide were investigated.The optimal determination conditions of hydrogen peroxide by cerium sulfate spectrophotometrywere obtained as follows:wavelength of 316 nm,cerium sulfate concentration of 0.002 mol·L^(-1),pH=0.4,and reaction time of 6 min.The cerium sulfate spectrophotometry and common titanium potassium oxalate spectrophotometry wereusedto determine hydrogen peroxide of 50.00 mg·L^(-1),respectively.The relative mean deviation,relative error,standard deviation and relative standard deviation of the former are significantly lower than those of the latter.The potassium titanate oxalate spectrophotometric method cannot determine the low concentration of hydrogen peroxide in 0~5.00 mg·L^(-1),while the standard curve R^(2)of the cerium sulfate spectrophotometric method in this concentration range is 0.9990.The detection limit is 0.11 mg·L^(-1),the spiked recovery rate is 99.1%~104.1%,and the relative standard deviation is 0.42%,reflecting good sensitivity,accuracy and precision.