依来络兰黑R褪色光度法测定痕量铜

PHOTOMETRIC DETERMINATION OF TRACE AMOUNTS OF COPPER BY THE COLOR FADING REACTION OF ERIOCHROME BLUE BLACK R

在氨水介质中 ,微量铜可催化亚硝酸钠氧化依来络兰黑 R褪色 ,由此建立了一种高灵敏度光度法测定微量铜的方法。间接摩尔吸光系数 ε530 =2 .5× 1 0 6L· mol-1·cm-1,线性范围为 0～ 8μg/2 5ml,线性回归方程 ΔA=0 .0 1 2 3C+0 .0 0 76,r=0 .9994,方法用于环境废水中微量铜的测定 ,选择性好 ,灵敏度高 。

It is found that in an ammoniacal medium, the oxidation reaction of NaNO 2 and eriochrome blue black R (EBB R) is catalyzed by trace amounts of copper(Ⅱ), leading to the color fading of EBR. On this basis, a highly sensitive photometric method for the determination of trace amounts of copper is proposed. Linear relationship between the concentration of Cu 2+ and the Δ A holds over the range of 0~8μg/25ml. Its linear regression equation is Δ A=0.0123C+0.0076 (r =0.9994). The indirect apparent molar absorptivity is found to be 2.6×10 6L·mol -1 ·cm -1 at 530nm. The reported method has been satisfactorily applied to the determination of traces of copper in waste water.