高灵敏度光度法快速测定电镀废水中的痕量钴

Determination of trace cobalt in electroplating effluent with high sensitive spectrophotometry

采用分光光度法测定电镀废水中痕量钴的含量。介绍了该方法的分析步骤,探讨了测量波长的确定,酸度、显色剂浓度、增溶剂浓度、配合物的抗酸性、EDTA和共存金属离子等因素对测量结果的影响。结果表明,在pH值为3 5～8时,钴与5-Br-PADAP生成紫红色配合物,在595nm吸收波长下,钴浓度在0～12μg/25mL范围内所测吸光度值与钴浓度间的关系遵守比耳定律。该方法准确度高,回收率达96 4%～102 2%。

Trace cobalt in electroplating effluent was determined by means of high sensitive spectrophotometry. Measuring procedures were described in detail. Measuring wave length was optimized by experiments. The effects of acidity, concentration of chromogenic agent and solubilizing agent, acid resistance of complex compound, EDTA, and co existing metal ions on the measuring results were studied. Results show that an amaranth compound is obtained while cobalt complexing 5 Br PADAP with pH value of 3 5～8, and the measured absorbance to cobalt content curve follows Beer's law under 595nm measuring wave length and cobalt content of 0～12 μg/25 mL. This method has high accuracy with recovery rate of 96 4%～102 2%.