维多利亚蓝B-铜钨杂多酸-聚乙烯醇体系光度法测定铜

PHOTOMETRIC DETERMINATION OF COPPER BY THE ION-ASSOCIATION COMPLEX REACTION BETWEEN Cu-W HETEROPOLY ACID AND VICTORIA BLUE B IN THE PRESENCE OF PVA

在聚乙烯醇存在下 ,铜钨杂多酸与维多利亚蓝 (VBB)形成三元离子缔合物 ,表观摩尔吸光系数ε=3.1 0× 1 0 6L· mol-1· cm-1,最大吸收波长位于 590 nm,铜量在 2～ 1 2μg· L-1范围内服从比耳定律 ,摩尔组成比 Cu( )∶W∶VBB=1∶ 1 2∶ 1 ,大多数常见离子不干扰 ,方法用于纯铝和自来水中铜的测定 。

It is found that in a dilute sulfuric acid medium, and in the presence of PVA 124, an ion association complex is formed between Cu W heteropoly acid and victoria blue B, the absorption maxima of which is found to lie at 590nm. The apparent molar absorptivity of this complex is found to be 3.10×10 6L·mol -1 ·cm -1 . Beer′s law is obeyed in the range 2~12μg of Cu 2+ per 1L of solution. Most of the common co existing ions do not interfere the determination of copper. The proposed method has been used in the determination of copper in pure aluminum and in tap water.