化学学报 ›› 1980, Vol. 38 ›› Issue (5): 423-432. 上一篇    下一篇

论文

铜在玻璃碳电极上的阴极伏安特性及其在铜矿分析中的应用

金文睿, 张子忠, 史爱军   

  1. 山东大学化学系 济南
  • 投稿日期:1978-10-31 发布日期:2013-06-03

THE CATHODIC VOLTAMMETRIC CHARACTERISTICS OF COPPER AT THE GLASSY CARBON ELECTRODE AND ITS APPLICATION IN THE ANALYSIS OF COPPER-CONTAINING MINERALS

JIN WEN-RUI, ZHANG ZI-ZHONG, SHI AI-JUN   

  1. Department of Chemistry, Shandong University, Jinan
  • Received:1978-10-31 Published:2013-06-03

本文研究了NH3-NH4Cl溶液中铜在稳定玻璃碳电极上的线性变势阴极伏安特性.确定铜氨络离子在玻璃碳电极上的还原分两步进行.在2.5MNH3-0.75MNH4Cl中,第一个波是Cu(NH3)42+可逆地还原到Cu(NH3)2+,其峰电势为-0.28伏,与理论值一致.峰电流与电势变化速度及浓度的关系符合Randles-evcik方程.第二个波是Cu(NH3)2+不可逆地还原为铜,当电势变化速度改变时,其峰电势在-0.69~-0.84伏之间.第一个波峰电流的相对标准误差不大于±2.4%,温度系数约为+1.3%/度.本文在氨性底液中用铜在玻璃碳电极上还原的第一个波以测定铜矿中的铜.在极谱法中用的第二个波有[Co(NH3)6]3+前波及Tl+重波,它们在第一个波中均变为后波,从而克服了它们对铜测定的干扰.测定结果与标准样的数据吻合,与示波极谱的数据一致.测定矿样的相对标准误差在±0.37~3.2%之间,符合矿石分析的要求.

The catbodic voltammetric charaatoristics of copper with linearly changing tension at the glassy carbon electrode in NH3-NH4Cl were studied in detail.The electrode reaction,peak tension,reversibility,peak current and temperature coeflioient were investigated.Experimental results showed that the reduotion of cuprammine complex cation was proceeded stepwisely at the glassy carbon electrode.Cu(NH3)2+4 was first reduced reversibly to Cu(NH3)2+,then to Cu irreversibly.