Panwar A, Baniwal S, Sharma C L, Singh A K
Department of Chemistry, University of Roorkee, India.
Fresenius J Anal Chem. 2000 Dec;368(8):768-72. doi: 10.1007/s002160000601.
A polystyrene based membrane of 3,4:12,13-dibenzo-2,5,11,14-tetraoxo- 1,6,10,15-tetraazacyclooctade-cane shows a Nernstian response to Cd(II) ions over a wide concentration range (3.16 x 10(-6) - 1.00 x 10(-1) mol L(-1) with a Nernstian slope of 29.8 mV/decade of concentration, between pH 2.0 and 6.0. This electrode has been found to be chemically inert and of adequate stability with a response time of 20s. The electrode gives reproducible results with a lifetime of 130 days. The membrane works satisfactorily in a partially non-aqueous medium up to a maximum 35% (v/v) content of methanol and ethanol. The practical utility of the proposed chemical sensor has been observed by using it as end-point indicator in the titration of Cd(II) ions with EDTA. The potentiometric selectivity coefficient values indicate that the membrane sensor is highly selective for Cd(II) ions over a number of cations. Small amounts of surfactants do not disturb the functioning of the sensor. This electrode has also been used to estimate cadmium ions in real samples.
一种基于聚苯乙烯的3,4:12,13-二苯并-2,5,11,14-四氧代-1,6,10,15-四氮杂环十八烷膜在较宽的浓度范围（3.16×10⁻⁶ - 1.00×10⁻¹ mol L⁻¹）内对Cd(II)离子呈现能斯特响应，能斯特斜率为29.8 mV/浓度 decade，pH范围在2.0至6.0之间。已发现该电极化学惰性良好，稳定性足够，响应时间为20秒。该电极给出的结果具有可重复性，寿命为130天。该膜在甲醇和乙醇含量最高达35%（v/v）的部分非水介质中能令人满意地工作。通过将所提出的化学传感器用作Cd(II)离子与EDTA滴定的终点指示剂，观察到了其实际应用价值。电位选择性系数值表明该膜传感器对Cd(II)离子相对于多种阳离子具有高度选择性。少量表面活性剂不会干扰传感器的功能。该电极还用于估计实际样品中的镉离子。
