6-硝基-2-苯并噻唑重氮氨基偶氮苯与铜的显色反应及其应用

The Chromogenic Reaction of 6-nitro-2-benzothiazolyl- diazoaminoazobenzene with Copper and Its Application

在pH10～12的Na2B4O7-NaOH缓冲溶液中,TritonX-100表面活性剂存在下,6-硝基-2-苯并噻唑重氮氨基偶氮苯与铜发生显色反应,生成2∶1的深红色配合物。配合物的最大吸收峰位于535nm处,表观摩尔吸光系数1.42×105L·mol-1·cm-1。Cu2+的浓度在0～400μg/L符合比尔定律。用拟定方法测定铝合金及铜矿石样品中的微量铜,结果与原子吸收法结果相符,6次测定的RSD<3%。

The chromogenic reaction of 6-nitro-2-benzothiazolyldiazoaminoazobenzene with copper and its application have been discussed in this paper. In the buffer solution of Na_(2)B_(4)O_(7)-NaOH (pH 10.0～12.0) and with the existence of surface active agent of Triton X-100, 6-nitro-2-benzothiazolyldiazoaminoazobenzene reacts with copper to form a red complex with molar ratio of Cu^(2+)∶NBTDAA=1∶2. The absorption maximum of the complex lies at 535 nm with an apparent molar absorptivity of 1.42×10^(5) L·mol^(-1)·cm^(-1).The Beer's law is obeyed in the concentration rang of 0～400 μg /L for copper.The method has been applied to the determination of trace copper in aluminium alloys and copper ores. The results are in agreement with those determined by AAS with precision of<3%RSD(n=6).