5—Br—PADAP—H2O2一阶导数光度法测定钢铁和铝合金中的钒

研究了5-Br-PADAP-H_2O_2一阶导数吸光光度法测定钒的适宜条件和有关参数.显色反应的适宜pH值为0.5～2.0,求导的参数是狭缝宽度2nm,微分宽度△λ=10nm,扫描速度为120nm/min,扫描范围550～650nm,确定一阶导数光谱在583nm处有一波峰,在615nm有一波谷,利用峰-峰法测定钒.本法不仅有高的灵敏度,而且有很强的抗干扰能力,选择性更高.用于钢铁和铝合金中微量钒的测定,得到满意的结果.

FIRST-ORDER DERIVATIVE SPECTROPHOTOMETRIC DETERMINATION OF MICROAMOUNTS OF VANADIUM IN IRON, STEEL AND ALUMINIUM ALLOY WITH 5-Br-PADAP AND H2O2

The suitable conditions and relative parameters of the first-order derivative spectrophototnetric determination of vanadium with 5-Br-PADAP and H2O2 has been studied. The optimum pH range is between 0.5 and 2.0 for the colour reaction'. The parameters of derivation are slit width = 2nm, differential width A = 10nm( scanning speed 120 nm/min,arid scanning range 550-650 rim. The first-order derivative spectrum shows a positive peak at 583 nm and a negative peak at 615 nm. The measurement was made by the "peak-peak method". It is not only sensitive and has strong anti-iriterfere abiltity and so this method has highler selectivity than normal spectrophotometry, This method is satisfactory for applying to determination of microamounts of vanadium in iron, steel and aluminium alloy.