钒-结晶紫体系催化动力学光度法测定烧结矿中痕量钒(Ⅴ)

Catalytic kinetic spectrophotometric determination of trace vanadium(Ⅴ) in sinter by vanadium-crystal violet system

基于以柠檬酸为活化剂，在硫酸介质中钒㈤能灵敏地催化高碘酸钾氧化结晶紫的褪色反应，建立了一种测定痕量钒（Ⅴ）新催化光度分析方法。在最佳实验条件下，催化反应吸光度与非催化反应吸光度的差值△A与V（Ⅴ）的质量浓度（ρ）在0～0．06μg／mL范围内呈良好的线性关系，方法的检出限为5．421×10^-10g／mL。对0．04μg／mL V（Ⅴ）测定的相对标准偏差为1．2%（n=11）。该催化反应对钒（Ⅴ）为一级反应，总反应为准一级反应，表观速率常数为2．055×10^-4／s，表观活化能为50．05kJ／mol。方法用于炼钢烧结矿样品中痕量钒（Ⅴ）的测定，回收率在100％～101%之间。

This paper focused on the determination of trace vanadium（Ⅴ） by catalytic kinetic spectropho- tometric method. Based on its oxidative fading reaction of crystal violet and potassium periodate in sulfuric acid medium, a new method for the determination of trace vanadium was established in the presence of citric acid as activator. The mass concentration of vanadium（V） ρ remained good linear relationship with △A in the range of 0-0.06μg/mL. The detection limit was 5. 421× 10^ 4 μg/mL. Relative standard deviation of the determination of 0.04 μg/mL V（V） RSD was 1.24 % （ n =11）. The catalytic reaction was first-order reaction. The whole reaction was pseudo first order reaction. The apparent ratio constant was 2. 055×10 ^-4/s and the apparent active energy was S0.05 kJ/mol. The method is of good selectivity and high sensitivity. The recovery ratio was between 100 %- 101% in the determination of trace vanadium（Ⅴ） in sample sinter steel.