过量酸性铬蓝K隐色光度法测定钴的研究

Spectrophotometric Determination of Cobait by Hiding Colour of the Excessive Acid Chrome Blue K

在 pH3.10的 HAc-NaAc 介质中,酸性铬蓝 K 与 CO^(2+)形成稳定的红色络合物.络合物组成为1:1。以 H_2O_3为隐色剂可以隐去过量显色剂的颜色,消除了高色度背景的影响,从而建立了一个光度法测定钻的新方法.方法已应用于测定钢样中的钻,结果满意.

This article has studied that Co^(2+) can reacts with acid chrome blue K to form a stable complex in HAc-NaAc buffer(pH3.10).The precision and sensitivity are increased by hiding the background colour of the excessive acid chrome blue K with H_2O_2 The maximum absorption is at 530nm.The molar absorptivity is 1.2×10~4.Beer's law is obeyed in the range 0-1.6μg/ml of cobalt.The method has been applied to the determination of microamounts of cobalt in steel with satisfactory results.