【摘要】 本文用示差脉冲极谱技术研究Pb(Ⅱ) 络合剂(β N 三丙酸)体系。依据实验得到的极谱峰电位的移动随溶液pH值的变化关系曲线,建立合适的金属络合物体系模型。用计算机分析程序,通过求解体系的质量平衡方程及拟合实验络合物形成曲线,优化得到金属络合物的稳定常数。计算机分析结果表明,在所研究的pH值范围内,溶液中存在四种金属络合物:PbH2L+、PbHL、PbL-、PbL(OH)2-,其稳定常数(logβ)分别为:16.23±0.04、12.42±0.01、4.11±0.05、9.43±0.02。更多还原

【Abstract】 In this paper, the Pb（Ⅱ）-Ligand（nitrilotri-3-propanonic acid） complex system was studied by differential pulse polarography （DPP） at lead total concentration 1.00×10^-5～5.00×10^-5mol/L, fixed total-ligand to total-metal concentration ratio 500～3000 and various pH values. An appropriate model for the metal complex system is constructed according to the observed shift in peak potential. Using the computer analytical program, stability constants of metal complexes are obtained by solving the mass-balance equation and fitting the complex formation curve. Four lead complexes PbH₂L⁺, PbHL, PbL^-, PbL（OH）^2-, and their corresponding stability constants as logβ 16.23±0.04,12.42±0.01,4.11±（0.05,9.43）±0.02, are reported.更多还原