化学学报 ›› 2006, Vol. 64 ›› Issue (21): 2185-2189. 上一篇    下一篇

研究论文

新型双核铜金属配合物为中性载体的硫氰酸根离子高选择性电极的研究

归国风, 柴雅琴, 袁若*, 孙爱丽, 王福昌   

  1. (西南师范大学化学化工学院 重庆市现代分析化学重点实验室 重庆 400715)
  • 投稿日期:2005-09-02 修回日期:2006-07-12 发布日期:2006-11-14
  • 通讯作者: 袁若

Study on New Highly Selective Thiocyanate Electrode Based on Dinuclear Copper Complex as Neutral Carriers

GUI Guo-Feng; CHAI Ya-Qin; YUAN Ruo*; SUN Ai-Li; WANG Fu-Chang   

  1. (Chongqing Key Laboratory of Analytical Chemistry, College of Chemistry and Chemical Engineering, Southwest University, Chogqing 400715)
  • Received:2005-09-02 Revised:2006-07-12 Published:2006-11-14
  • Contact: YUAN Ruo

研制了基于N,N'-亚乙基(μ-5,5-亚甲基-二水杨醛根)(乙酰丙酮根)合二铜(II) [Cu2(II)-MDSBAE]金属配合物为中性载体的阴离子选择性电极. 试验表明, 以Cu2(II)-MDSBAE金属配合物为中性载体的电极对SCN-具有良好的电位响应特性, 且呈现反Hofmeister行为,其选择性序列为: SCN->Sal->I->ClO4->NO3->Br->NO2->Cl-≈SO32->SO42-. 在pH 5.0的磷酸盐缓冲体系中, 电极电位呈现近能斯特响应, 线性响应范围为1.0×10-6~1.0×10-1 mol/L, 斜率为-53. 6 mV/dec (25 ℃), 检测下限为8.1×10-7 mol/L. 用交流阻抗研究了电极的响应机理, 并用紫外可见光谱技术测定了电极载体与SCN-, Sal-, I-, ClO4-和NO3-离子间的配位数及缔合常数. 将该电极用于实验室废水和工业废水中硫氰酸根的检测, 其结果令人满意.

关键词: 铜(II)配合物, 中性载体, 硫氰酸根, 离子选择性电极

A highly thiocyanate-selective poly(vinyl chloride) (PVC) membrane electrode based on N,N'-ethylidene(μ-5,5-methylene-disalicylaldehyde)-acetylacetonedicopper(II) [Cu2(II)-MDSBAE] complex as neutral carrier is reported. The electrode displays a preferential potentiometric response to thiocyanate and an anti-Hofmeister selectivity sequence in following order: SCN->Sal->I->ClO4->NO3->Br->NO2->Cl-≈SO32->SO42-. The electrode exhibits near Nernstian potential linear range of 1.0×10-6~1.0× 10-1 mol/L with a detection limit of 8.1×10-7 mol/L and a slope of -53.6 mV/decade in pH 5.0 of phosphorate buffer solution at 25 ℃. The response mechanism is discussed in view of the alternating current (A.C.) impedance technique. The coordination number and assiociation constants of axial coordination reaction of complex Cu2(II)-MDSBAE towards SCN-, Sal-, I-, ClO4- and NO3- were measured by means of the UV spectroscopy technique. The electrode was applied to thiocyanate ion in waste water analysis with satisfactory results.

Key words: copper(II) complex, neutral carrier, thiocyanate, ion-selective electrode