The Influence of Nanoscale Material on Response Properties of Iodide Selective Electrodes

Modified carbon paste iodide selective electrode following incorporation of novel mercury complex named as bis(3-phenyl-2-methylpropenaldehydene)-1,2-ethanediaminemercury(II)bromide[HgLBr2] has been reported. In general, in carbon paste electrode, the significant variables are pH, amount of ionophore, carbon paste, nujol, nanoparticles, and the type and amount of lipophilic cationic and anionic additives that their influence was optimized by one at a time optimization approached. It was found that incorporation of nanoscale material to carbon paste composition lead to significant improvement in the response properties of proposed electrodes. At optimum value of the variables, the electrodes exhibited near-Nernstian slopes of -59.41 ± 1.86 and -58.91 ± 2.08 mV/decade of iodide concentration over the range 5.0 × 10^-8 - 1.0 × 10^-1 M and 3.0 × 10^-8 -1.0 × 10^-1 M with detection limits of ~2.0 × 10^-8. The proposed electrodes have fast response times (<;10 s), satisfactory reproducibility (RSD5 <; 3%) with stable response over at least two months, while their responses are independent of pH over the range 2.5-10.5 for all nanoscale materials.