多溴代不对称变色酸双偶氮类显色剂与铋显色反应的研究及分析应用

Spectrophotometric Studies on the Colour Reaction of Asymmetrical Chromotropic Acid with Bi ( Ⅲ ) and Its Application

本文报道了四种不同的多溴代变色酸双偶氮类显色剂与Bi(Ⅲ)的显色反应.在高氯酸介质中,试剂与Bi(Ⅲ)形成稳定的蓝紫色配合物,反应的酸度范围宽,灵敏度高,尤以5-BPA-TB为最佳,其表观摩尔吸光系数达9.4×10~4,选择性亦好.用该方法测定了黄铜及紫铜样品中的痕量铋,与标准值符合,结果令人满意.

The colour reactions of four multi-bromo substituted asymmetrical biazo reagents of chro-motropic acid have been studied. The reagents react with Bi(Ⅲ) to form stable blue complexes ia perchloric acid medium.The colour reactions take place rapidly with a large contrastihigh sensitivityt and fair selectivity.The molar absorptivity of S-BPA-TB complex with Bi(Ⅲ) is 9.4×104L cm-1 mol-1 at 635nm.The calibration curve obeys Beer's law in the range of 0-25ug/25ml for bismuth complex.