5-(4-二乙氨基苯偶氮)-8-羟基喹啉与钒(Ⅴ)显色反应的研究及应用

Study on the Colour Reaction of Vanadiun (Ⅴ) with 5-(4-Diethylaminophenylazo)-8-hydroxyquinoline and Its Application

研究了5-(4-二乙氨基苯偶氮)-8-羟基喹啉(DEPAQ)与钒(Ⅴ)的显色反应。结果表明,在TritonX-100存在下,pH5.0～7.0的缓冲介质中,钒(Ⅴ)与DEPAQ形成1:2的红色络合物,最大吸收波长为525nm,表观摩尔吸光系数ε=4.74×10~4L·mol^(-1)·cm^(-1)。钒含量在0～30μg/25ml范围内符合比尔定律。在CyDTA和氟化钠存在下,用于钢铁样品中钒的测定,结果令人满意。

The colour reaction of 5-(4-diethylaminopheuylazo)-8-hydroxyquinoline (DBPAQ) with vanadium (Ⅴ) has been studied. In the presence of Triton X-100, vanadium (Ⅴ) reacts with DEPAQ to form a stable 1: 2 complex within pH5.0-7.0. The complex exhibits a maximum absorption at 525nm with an apparent molar absorptivty of 4.74×10~4 L·mol^(-1)·cm^(-1). Beer's law is obeyed in the range of 0-30μg V(Ⅴ)/25ml. The interference of common ions can be eliminated by the mixture of CyDTA and NaF. The method is applied to the determination of vanadium in steel samples with satisfactory results.