紫外分光光度法测定聚硫密封胶中二氧化钛

基于强酸性溶液中钛氧离子与H2O2发生显色络合反应的原理,建立了浓硫酸–硫酸铵消解–紫外分光光度法测定聚硫密封胶中TiO_2含量的方法。通过对酸液和显色剂用量,以及显色络合物稳定性的系统考察,确定浓硫酸用量为2 mL,双氧水用量为3 mL,检测波长为403 nm。二氧化钛质量浓度在0~130μg/mL范围内与其吸光度呈良好的线性关系,线性方程为A=5.047 8c–0.019 31,r~2=0.999 2,检出限为0.08μg/mL。检测结果的相对标准偏差为0.89%(n=5),3水平加标平均回收率为101.7%。该方法线性范围较宽、检出限低、重复性好,可用于聚硫密封胶中二氧化钛的定量分析。

Determination of Titanium Dioxide in Polysulfide Sealant by UV Spectrophotometry

Based on the principle of chromogenic complexation reaction between titanium oxygen ions and hydrogen peroxide in the strong acidic solutions,a method for the determination of titanium dioxide in polysulfide sealant was established by concentrated sulfuric acid-ammonium sulfate digestion-ultraviolet spectrophotometry. According to the experimental results of some factors such as the usage of inorganic acid,chromogenic reagent and the stability of chromogenic complexes,the usage of H2SO4 and H2O2 were determined to be 2 mL and 3 mL,respectively,and the wavelength for UV detection was 403 nm. Under the optimum conditions, TiO2 concentration was linear with the ultraviolet absorbance in the range of 0-130μg/mL. The linear equation wasA=5.0478c-0.01931 with correlation coefficent (r2) of 0.9992. The method detection limit was 0.08μg/mL. The relative standard deviation of parallel experiment results was 0.89%(n=5),and the average recovery of TiO2 was 101.7%. The method has wide linear range,low detection limit,good reproducibility,it is suitable for quantitative analysis of titanium dioxide in polysulfide sealant.