Hassan Saad S M, Abou Ghalia M H, Amr Abdel-Galil E, Mohamed Ayman H K
Department of Chemistry, Faculty of Science, Ain Shams University, Cairo, Egypt.
Talanta. 2003 May 28;60(1):81-91. doi: 10.1016/S0039-9140(03)00038-9.
New membrane sensors with cylindrical configuration for lead (II) ions are described based on the use of three newly synthesized pyridine carboximide derivatives as neutral ionophores in plasticized PVC membranes. The sensors exhibit significantly enhanced response towards lead (II) ions over the concentration range 4x10(-6)-1x10(-2) mol l(-1) at pH 4.5-7 with a lower detection limit of 0.4-3.7 mug ml(-1). The sensors display near-Nernstian slope of 26.0-33.1 mV per decade for Pb(II) ions. Effects of plasticizers, lipophilic salts and various foreign common ions are tested. The sensors show long life span, good selectivity for Pb(II) over a wide variety of other metal ions, long term stability, high reproducibility, and fast response. Validation of the method by measuring the lower detection limit, range, accuracy, precision, repeatability and between-day-variability reveals good performance characteristics of the proposed sensors. The sensors are used for direct determination of lead in stack emissions of lead smelters, assay of lead in rocks and monitoring of potentiometric titration of Pb(II) with EDTA. The results obtained agree fairly well with data obtained by atomic absorption spectrometry.
本文描述了一种用于检测铅（II）离子的新型圆柱形膜传感器，该传感器基于三种新合成的吡啶甲酰亚胺衍生物作为中性离子载体，应用于增塑PVC膜中。在pH值为4.5 - 7的条件下，该传感器对铅（II）离子在4×10⁻⁶ - 1×10⁻² mol l⁻¹浓度范围内表现出显著增强的响应，检测下限为0.4 - 3.7 μg ml⁻¹。该传感器对Pb（II）离子显示出近能斯特斜率，每十倍浓度变化为26.0 - 33.1 mV。测试了增塑剂、亲脂性盐和各种外来常见离子的影响。该传感器具有寿命长、对Pb（II）离子相对于多种其他金属离子具有良好的选择性、长期稳定性、高重现性和快速响应等特点。通过测量检测下限、范围、准确度、精密度、重复性和日间变异性对该方法进行验证，结果表明所提出的传感器具有良好的性能特征。这些传感器用于直接测定铅冶炼厂烟囱排放物中的铅、岩石中铅的测定以及用EDTA电位滴定法监测Pb（II）。所得结果与原子吸收光谱法获得的数据相当吻合。
