新显色剂1-偶氮苯-3-(5-氯-2-吡啶)-三氮烯的合成及其与镉的显色反应

Synthesis of a new reagent 1-azobenzene-3-(5-chloro-2-pyridyl)-triazene and its color reaction with Cadmium

报道了新显色剂1 偶氮苯3 (5 氯2 吡啶) 三氮烯的合成及其与镉的显色反应研究。在TX 100表面活性剂存在下,pH11.0的Na2B4O7 NaOH缓冲溶液中,该试剂与镉发生显色反应,生成3∶1的红色配合物。配合物的最大吸收峰位于530nm,表观摩尔吸光系数为2.42×105L·mol-1·cm-1。Cd2+质量浓度在0～480μg/L范围内符合比尔定律。用拟定方法可测定人发和废水中的微量镉。

<Abstrcat>1-azobenzene-3-(5-chloro-2-pyridyl)-triazene (ABCPDT) as a chromogenic reagent was synthesized and its color reaction with cadmium was investigated. In the presence of the surfactant Triton X-100 and in the Na_2B_4O_7-NaOH medium of pH 11.0, ABCPDT forms a red complex with Cd(Ⅱ). The apparent molar absorbtivity of the complex is 2.42×10~5 L·mol^(-1)·cm^(-1) at 530 nm(λ_(max)). The molar ratio of Cd(Ⅱ) to ABCPDT is 1∶3. Beer′s law is well obeyed in the range of 0～480 (μg/L) of cadmium. The method was applied to the direct determination of cadmium in the hair and practical samples with satisfactory results.