Department of Chemistry, Universitat Autònoma de Barcelona, Bellaterra, Catalonia, Spain.
J Hazard Mater. 2010 Sep 15;181(1-3):140-6. doi: 10.1016/j.jhazmat.2010.04.107. Epub 2010 May 2.
Two PVC membrane ion selective electrodes for Pb(II) ion based on two bis-thioureas: 1,3-bis(N'-benzoylthioureido)benzene and 1,3-bis(N'-furoylthioureido)benzene as ionophores, are reported. A first membrane formulated using 1,3-bis(N'-benzoylthioureido)benzene as carrier exhibited a Nernstian response to Pb(II) over a wide concentration range (4.0x10(-6) to 1.0x10(-2)M) with a slope of 31.5+/-1.6 mV/dec. It showed a fast response time (t(90%)=14 s) and could be used for 10 weeks without any divergence in potentials. The membrane formulated using 1,3-bis(N'-furoylthioureido)benzene as carrier exhibited a Nernstian response in the concentration range (5.0x10(-6) to 1.0x10(-2) M), with a slope of 30.0+/-1.3 mV/dec. Its response time was t(90%)=14 s, and it could be used for 14 weeks without any divergence in potentials. The two proposed potentiometric sensors revealed acceptable selectivities for Pb(II) over a wide variety of other metal ions and could be used in a pH range of 2.2-6.0. Both electrodes were assayed in direct potentiometric determination of lead in soils (10-30 mg/kg range) with very good performance (0.99935 correlation coefficient in the comparison against ICP-MS method).
两种基于双硫脲的 PVC 膜离子选择性电极用于测定 Pb(II)离子：1,3-双（N'-苯甲酰基硫脲基）苯和 1,3-双（N'-呋喃甲酰基硫脲基）苯作为离子载体。使用 1,3-双（N'-苯甲酰基硫脲基）苯作为载体的第一种膜对 Pb(II)表现出宽浓度范围（4.0x10(-6)至 1.0x10(-2)M）的 Nernst 响应，斜率为 31.5+/-1.6 mV/dec。它具有快速的响应时间（t(90%)=14 s），并且可以在没有任何电位漂移的情况下使用 10 周。使用 1,3-双（N'-呋喃甲酰基硫脲基）苯作为载体的膜在浓度范围（5.0x10(-6)至 1.0x10(-2) M）内表现出 Nernst 响应，斜率为 30.0+/-1.3 mV/dec。其响应时间为 t(90%)=14 s，并且可以在没有任何电位漂移的情况下使用 14 周。这两种提出的电位传感器对 Pb(II)具有广泛的其他金属离子的可接受选择性，并且可以在 pH 范围为 2.2-6.0 下使用。两种电极都在直接电位法测定土壤中的铅（10-30 mg/kg 范围内）中进行了测定，性能非常好（与 ICP-MS 方法相比，相关系数为 0.99935）。
