在弱酸介质中钒(V),3,5-Br_2-PADAP与羟胺生成组成为1:1:1的蓝色三元络合物,其吸收峰位于610纳米,摩尔消光系数为6.0×10~4,该络合物的生成与试剂的加入顺序有关,并且一经形成后十分稳定,不为强无机酸所破坏,据此拟订了测定微量钒的方法,方法灵敏度高,选择性好,钴干扰可通过改变试剂加入顺序得以消除,经试用于工业废水和土壤中微量钒的测定,取得良好结果。 The blue ternary complex of vanadium (V), 3,5-Br_2-PADAP and hydroxylamine with the ratio of 1: 1: 1 in weak acid medium has an absorption peak at 610 nm and a molar extinction coefficient of 6.0 × 10 ~ The formation of the complex is related to the order of addition of the reagents, and once formed, it is stable and not damaged by the strong inorganic acid. Thus, a method for determination of trace vanadium is developed. The method has high sensitivity, good selectivity and cobalt interference It can be eliminated by changing the order of adding reagents, and good results have been obtained after the determination of trace vanadium in industrial wastewater and soil.