Thermal Studies of New Lead(II) Coated‐Wire Membrane Electrodes

Five plastic membrane Pb 2+ ‐selective electrodes were prepared based on 1,4‐bis( N ‐tosyl‐ o ‐aminophenoxy)butane I , 1,4‐bis( N ‐allyl‐ N ‐tosyl‐ o ‐aminophenoxy)butane II , 1,4‐bis( N ‐benzyl‐ N ‐tosyl‐ o ‐aminophenoxy)butane III , 1,4‐bis[ N ‐( o ‐allyloxybenzyl)‐ N ‐tosyl‐ o ‐aminophenoxy]butane IV , and 1,4‐bis( N ‐octyl‐ N ‐tosyl‐ o ‐aminophenoxy)butane V as neutral carriers. The electrodes exhibited nearly Nernstian responses over the concentration ranges, 2.5×10 −4 –4.0×10 −2 , 2.5×10 −5 –4.0×10 −2 , 7.9×10 −5 –4.0×10 −2 , 2.2×10 −5 –4.0×10 −2 , and 1.9×10 −4 –4.0×10 −2 M for electrodes composed with the ionophores I–V , respectively. All electrodes showed pH range of about 4.0 to 11.5 and working temperature range of 22 to 70 °C with isothermal temperature coefficients of 1.19×10 −3 , 1.16×10 −3 , 1.16×10 −3 , 1.00×10 −3 , and 1.32×10 −3 V/°C for electrodes I–V respectively.