Yaftian Mohammad Reza, Rayati Saeed, Emadi Daryoush, Matt Dominique
Department of Chemistry, Faculty of Science, Zanjan University, Iran.
Anal Sci. 2006 Aug;22(8):1075-8. doi: 10.2116/analsci.22.1075.
The preparation of a lead-selective electrode based on 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis-(diphenylphosphinoylmethoxy)calix[4]arene (1) as an ionophore is reported. The plasticized PVC membrane containing 30% PVC, 57% ortho-nitrophenyloctylether (NPOE), 4% sodium tetraphenylborate (NaTPB) and 9% ionophore 1 was directly coated on a graphite electrode. It exhibits a nearly Nernstian slope of 28.0 +/- 0.2 mV decade(-1) over a concentration range of 1 x 10(-5) - 1 x 10(-2) mol dm(-3) with a detection limit of 1.4 x 10(-6) mol dm(-3). The response time of the electrode was found to be ca. 17 s. The potential of the sensor was independent of the pH variation in the range 3.5 - 5.0. The selectivity of the electrode performance towards lead ions over Th4+, La3+, Sm3+, Dy3+, Y3+, Ca2+, Sr2+, Cd2+, Mn2+, Zn2+, Ni2+, Co2+, NH4+ Ag+, Li+, Na+ and K+ ions was investigated. The prepared electrode was used successfully as an indicator electrode for a potentiometric titration of a lead solution using a standard solution of EDTA. The applicability of the sensor for Pb2+ measurements in various synthetic water samples spiked with lead nitrate was also checked.
报道了基于5,11,17,23-四叔丁基-25,26,27,28-四（二苯基膦酰甲氧基）杯[4]芳烃（1）作为离子载体的铅选择性电极的制备。将含有30%聚氯乙烯（PVC）、57%邻硝基苯基辛基醚（NPOE）、4%四苯基硼酸钠（NaTPB）和9%离子载体1的增塑PVC膜直接涂覆在石墨电极上。在1×10⁻⁵ - 1×10⁻² mol dm⁻³的浓度范围内，它表现出近能斯特斜率为28.0±0.2 mV/十倍浓度变化，检测限为1.4×10⁻⁶ mol dm⁻³。发现电极的响应时间约为17秒。传感器的电位在3.5 - 5.0的pH范围内与pH变化无关。研究了电极对铅离子相对于Th⁴⁺、La³⁺、Sm³⁺Dy³⁺、Y³⁺、Ca²⁺、Sr²⁺、Cd²⁺、Mn²⁺、Zn²⁺、Ni²⁺、Co²⁺、NH₄⁺、Ag⁺、Li⁺、Na⁺和K⁺离子的电极性能选择性。制备的电极成功用作指示电极，用于用乙二胺四乙酸（EDTA）标准溶液对铅溶液进行电位滴定。还检查了该传感器在加有硝酸铅的各种合成水样中测量Pb²⁺的适用性。
