钨(Ⅵ)-4-(2-苯并噻唑偶氮)邻苯二酚-OP三元络合物显色反应的研究

Studies on Chromogenic Reaction for Ternary Tungsten(Ⅵ)-4-(2-Benzothiazolylazo)Pyrocatechol-OP Micelle-Complex

在pH4.2～5.2范围内,有机试剂4-(2-苯并噻唑偶氮)邻苯二酚(BTAPC)与钨(Ⅵ)和非离子表面活性剂OP反应形成稳定的、带负电荷的、紫红色三元胶束络合物。该络合物中W(Ⅵ)与BTAPC的组成比为1:2;其λ_(max)为538nm,对比度(△λ)为106am;在pH4.8,25℃和μ0.1时,其表观稳定常数为7.44×10^(11),表观_(538)为7.38×10~4,真实ε_(538)为7.96×10~4。钨(Ⅵ)含量在0.04～1.3mg/L范围内遵从比尔定律。建议了络合物的结构。本法简便、快速、准确,用于合金钢试样中少量钨的测定,取得了满意的结果。

4-(2-Benzothiazolylazo) pyrocatechol (BTAPC), a new organic reagent, reacts with W (Ⅵ) and OP, a non-ionic surfactant, to form a stable, negatively charged, violet-red, ternary micelle-complex in the pH range of 4.2 to 5.2. The ratio between W(VI) and BTAPC in the complex is 1:2 with λ _max=538nm,contrast(Δλ) is 106nm,apparent stability constrant is 7.44×10~11,apparent ■is 7.38×10~4L·mol^(-1)·cm^(-1) and real ■is 7.96×10~4L·mol^(-1)·cm^(-1) in pH4.8,25℃ and μ0.1.Beer's law is obeyed in the range of 0.04 to 1.3mg of W(VI) per liter.The structure of the complex waw suggestes.The satisfactory results have been achieved in applying the analytical to the determination of low content tungsten in alloy steel