分光光度法测定金属镁中微量钒

Determination of trace vanadium in metallic magnesium by spectrophotometry with ternary complex of V- 5-Br-PADAP- H_2O_2

研究了在不同介质中V-5-Br-PADAP—H2O2三元络合物的性质，测定了该络合物的组成为：n（V）：n（5-Br—PADAP）-n（H2O2）=1：1：1，其最大吸收波长为585nm，在HN03和EDTA一柠檬酸铵介质中，络合物在pH1．4—2．4之间吸光度最大且平稳，表观摩尔吸光系数为5．43×10。。方法已用于测定金属镁中5．0×10 -4％～1．0×10 -2的钒。

The nature of ternary complex of V--5-Br-PADAP--H2O2 in different media was studied m tlals paper, V reacts with 5-Br-PADAP and H2 O2 to form a ternary complex, whose component ratio is n （V） ： n （5-Br- PADAP） ： n（ H202 ） = 1： 1：1 and the maximum absorption wavelength is 585 nm. Under the condition of pH 1.4 ~ 2. 4 in nitrate and EDTA-ammonium citrate medium, the complex has the maximum absorbance, the apparent molar absorption coefficient is 5.43 × 104. This analytical vanadium in magnesium in the rang of 5.0 × 10 -4 _ 1.0 × 10 method could be applied to the determination of vanadium in magnesium in the rang of 5.0 ×10 -4 _ 1.0 × 10 -2%.