摘要
研究了在1 mol/L磷酸介质中，钒(V)对KIO4氧化靛蓝胭脂红褪色反应的催化作用及草酸钠的活化作用，建立了一种测定钒的方法。无草酸钠时该体系为准零级反应，表观活化能为76.7 kJ/mol，在22℃时钒量在0～5mg/L范围内与?A呈线性，检出限为0.1 mg/L。在草酸钠存在下则为准一级反应，表观活化能为60.1 kJ/mol，钒量在0～mg/L范围内与1g(A0/A)呈线性，检出限为0.02mg/L。提高介质酸度，可显著降低反应温度。在NaF及尿素存在下，大多数常见离子无干扰。本法简便快速，选择性和灵敏度较高，用于钢中微量钒的直接测定，结果满意。
A kinetic method for the determination of V(V) was developed, based on the catalytic oxidation of indigo carmine w ith KIO4 in 1 mol/L H3PO4 medium. In the absence of Na2C2O4, it is a quasi-zero-order reaction, the apparent activation energy (Ea) is 76. 7kJ/ mol. The linear range and detection limit at 22℃ is 0～5mg/L and 0.1 mg/L, r espectively. In the presence of Na2C2O4, it is a quasi-1st-order reacti o n, and the oxidation of indigo carmine with KIO4 was accelerated, Ea=60 .1 kJ/ mol. The linear range and detection limit at 22℃ are 0～1 mg/L and 0.02 mg/ L, r espectively. In the presence of NaF and urea, most of the common ions did not in terfere. The method is selective and sensitive, and it was applied to the direct determination of trace vanadium in steels with satisfactory results.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2001年第9期1039-1042,共4页
Chinese Journal of Analytical Chemistry
