变色酸双偶氮胂酸型显色剂的合成及其与Pb^(2+)反应的光度性能研究

Synthesis of Bisarsenazo Type Reagents of Chromotropic Acid and Study on the Spectrophotometric Behaviors of Reaction of Reagents With Pb^(2+)

合成了八种变色酸双偶氨胂酸型显色剂，并对它们与Pb(2＋)反应的光度性能作了研究；研究结果表明，这些试剂与Pb(2＋)反应具有一定的灵敏度和选择性，反应一般在弱酸性介质中进行，发色瞬时，配合物稳定，最大吸收位于605nm左右。

In this article 8 new bisarsenazo type reagents of chromotropic acid have been synthesized. Their colour reactions with Pb(2+) have also been studied. The result is that reaction of these reagents and Pb(2+) have some certain sensitivity and choice. Normally the reaction is completed in weak acidic media. The color-appearnce is at instant and Pb-complexes are stable. Itsmaximum absorption lies at some 605 nm. The apparent absorption of coefficient is (2～3)× 104L. mol-1. cm-1. Usually Beer's law allows 0～150μg Pb/25 ml.