Singh Ashok Kumar, Saxena Puja
Department of Chemistry, Indian Institute of Technology-Roorkee, Roorkee-247667, India.
Talanta. 2005 May 15;66(4):993-8. doi: 10.1016/j.talanta.2004.12.059. Epub 2005 Jan 26.
A new highly Tl(I)-selective PVC membrane electrode based on tetrathia macrocycle 6,7: 14,15-dibenzo-5,8,13,16-tetraoxo-1,4,9,12-tetrathiacyclohexadecane [Bz(2)O(4)(16)aneS(4)] (I) as membrane carrier, o-nitrophenyloctyl ether (o-NPOE) as solvent mediator and potassium tetrakis(p-chlorophenyl)borate (KTpClPB) as lipophilic additive has been developed. The best performance was given by the membrane of macrocycle (I) with composition 3:120:1.5:50 (I:o-NPOE:KTpClPB:PVC). This electrode exhibits a Nernstian response to Tl(I) ions in the concentration range 1.0x10(-1)-2.23x10(-6)M with a slope of 58.2mV/decade of concentration and a detection limit of 1.58x10(-6)M. The response time of the sensor is 12s and can be used over a period of 4 months with good reproducibility. The proposed electrode revealed good selectivity over a wide variety of other cations including alkali, alkaline earth, heavy and transition metals. The electrode works well over a pH range of 3.2-11.5 and in partially non-aqueous medium with up to 30% organic content. The sensor was also used as an indicator electrode in potentiometric titration of Tl(I) ions with KI solution.
基于四硫大环化合物6,7:14,15-二苯并-5,8,13,16-四氧代-1,4,9,12-四硫杂环十六烷[Bz(2)O(4)(16)aneS(4)]（I）作为膜载体、邻硝基苯基辛基醚（o-NPOE）作为溶剂介质以及四（对氯苯基）硼酸钾（KTpClPB）作为亲脂性添加剂，研制出了一种新型的对Tl（I）具有高选择性的PVC膜电极。大环化合物（I）组成比例为3:120:1.5:50（I:o-NPOE:KTpClPB:PVC）的膜表现出最佳性能。该电极对Tl（I）离子在1.0×10⁻¹ - 2.23×10⁻⁶M浓度范围内呈现能斯特响应，浓度斜率为58.2mV/十倍浓度，检测限为1.58×10⁻⁶M。传感器的响应时间为12秒，可在4个月内良好重现性地使用。所提出的电极对包括碱金属、碱土金属、重金属和过渡金属在内的多种其他阳离子显示出良好的选择性。该电极在pH值为3.2 - 11.5的范围内以及在有机含量高达30%的部分非水介质中工作良好。该传感器还用作指示电极，用于用KI溶液电位滴定Tl（I）离子。
