新显色剂4-(6-溴-2-苯并噻唑偶氮)邻苯二酚-铁(Ⅱ)-OP 体系的分光光度研究

Studies on spectrophotometry of a new chromogenic reagent 4-(6-bromo-2-benzothiazolylazo)pyrocatechol-iron(Ⅱ)-OP.system

在pH 8.5～9.4的范围内,4-(6-溴-2-苯并噻唑偶氮)邻苯二酚(6-Br-BTAPC)与铁(Ⅱ)形成稳定的、带负电荷的紫色二元配合物。在 25℃、pH 9.0和μ0.1时,Fe(Ⅱ)-6-Br-BTAPC-OP 三元胶束配合物中 Fe(Ⅱ)与 6-Br-BTAPC 的组成比为1:3,表观稳定常数为7.7×10^(13),λ_(max)为635nm,对比度(△λ)95 nm,表观摩尔吸光系数ε_(635)高达1.23×10~5L·mol^(-1)·cm^(-1)。铁含量在0～16 μg/25 mL 范围内遵从比耳定律。用于工业用水和工业废水中痕量铁的分光光度测定,取得了满意的结果。

4-(6-Bromo-2-benzothiazolylazo)pyrocatechol(6-Br-BTAPC),a now chromogcnic.reagent,reacts with Fe(Ⅱ)to form a stable,violet,negatively charged,binary complex in the pHrange of 8.5 to 9.4.At 25℃,pH 9.0 and μ0.1,the ratio between Fe(Ⅱ)and 6-Br-BTAPC inthe Fe(Ⅱ)-6-Br-BTAPC-OP ternary-micelle-complex is 1:3 with an apparent stabilityconstant 7.7×10^(1(?)),λ_(max)635nm,the contrast(△λ)95nm and ε_(835)1.23×10~5L·mol^(-1)·cm^(-1).Beer'slaw is obeyed in the range of 0 to 16 μg of Fe(Ⅱ)per 25mL.Satisfactory results have beenachieved in applying the method to the spectro-photometric determination of traces of iron inindustrial water and waste water.