摘要
建立了加氢催化剂中钼含量的分光光度测定方法。采用Mo(Ⅵ)在浓硫酸介质中被硫脲还原为Mo(Ⅴ),Mo(Ⅴ)与硫氰酸钾生成橙红色配合物进行钼的测定。考察了检测波长、硫酸溶液加入量、还原剂用量、显色剂用量及显色时间对测定结果的影响。最佳测定条件为:检测波长460 nm;硫酸溶液(2.0 mol/L)、硫脲(100 mg/mL)、硫氰酸钾(250 mg/mL)的加入量分别为5.0,2.5,2.5 mL;显色时间30 min。在此条件下其标准曲线在0.500～8.000μg/mL范围内呈线性关系,回归方程为A=0.115C+0.0031,相关系数为r=0.9991。该方法回收率为93.67%～104.3%,RSD为0.19%。此方法操作简单,可用于加氢催化剂中钼含量的分析。
A spectrophotometric method for the determination of molybdenum（Ⅵ） in hydrogenation catalyst was established.The method was base on the fact that molybdenum（Ⅵ） could be reduced by thiourea to molybdenum（Ⅴ） in sulfuric acid medium.Then molybdenum（Ⅴ） could react with potassium thiocyanate to form salmon pink complex.In order to obtain optimal determination results,5 crucial determination parameters,including detection wavelength,color development time,dosages of chromogenic reagent,reducing agent and sulfuric acid,were investigated.Results showed that the optimal values of the above parameters were as follows： detection wavelength 460 nm,sulfuric acid 5.0 mL,thiourea（100 mg/mL） 2.5 mL,potassium thiocyanate（250 mg/mL） 2.5 mL,and color development time 30 min.Under these conditions,a good linear relationship between absorbance（A） and molybdenum（Ⅵ） concentration（C） in the range 0.500～8.000 μg/mL was observed,which could be expressed as A=0.115C＋0.003 1（r=0.999 1）,the recovery rate was 93.67%～104.3%,and RSD was 0.19%.The method has the merit of easy operation,and could be applied to the indirect determination of molybdenum（Ⅵ） in hydrogenation catalyst.
出处
《北京石油化工学院学报》
2010年第3期47-50,共4页
Journal of Beijing Institute of Petrochemical Technology
关键词
钼
硫氰酸钾
分光光度法
加氢催化剂
molybdenum
potassium thiocyanate
hydrogenation catalyst
spectrophotometry
