摘要
在硫酸介质中,活化剂柠檬酸存在时,于90℃的加热条件下,痕量钒(V)灵敏地催化高碘酸钾氧化亚甲基蓝褪色的指示反应。探讨了最佳实验条件,测定了动力学参数,建立了测定痕量钒(V)的新光度分析方法。研究发现,非催化反应吸光度(A0)与催化反应吸光度(A)在659 nm处的差值ΔA与钒(V)的质量浓度ρ在0.004~0.06μg/mL范围内呈良好的线性关系,检出限为1.78×10-10g/mL。该催化反应为准一级反应,反应的表观速率常数为9.03×10-4/s,表观活化能为60.92 kJ/mol。方法用于炼钢烧结矿样品中痕量钒(V)的测定,其回收率在101%~102%的范围,符合痕量分析的要求。
This paper focused on the determination of trace vanadium(V) by catalytic kinetic spectrophotometric method.In this method,the vanadium(V) could catalyze the fading reaction of the potassium periodate which acted on methylene blue in medium dilute sulfuric acid with citric acid as activator and under heating at 90 ℃.Under selected experimental conditions,the absorbence difference ΔA between non-catalytic reaction system(A0) and catalytic reaction system(A) at 659 nm remained good linear relationship with quality concentration ρ of vanadium(V) in the range of 0.1-1.5 μg/25 mL and the detection limit was 1.78×10-10 g/mL.The apparent ratio constance of the reaction was 9.03×10-4 /s,and the apparent active energy was 60.92 kJ/mol.This method has been applied to the determination of trace vanadium(V) in sinter samples.Its recovery was between 101%-102% which met the requirement of trace analysis.
出处
《冶金分析》
CAS
CSCD
北大核心
2010年第4期54-57,共4页
Metallurgical Analysis
关键词
催化动力学光度法
高碘酸钾
亚甲基蓝
钒(V)
烧结矿
catalytic kinetic spectrophotometry
potassium periodate
methylene blue
vanadium(V)
sinter