Selective Determination of Zn2+ Ion in Various Environmental, Biological and Medicinal Plant Samples Using a Novel Coated Graphite Electrode

Abstract Novel Zn 2+ ion‐selective PVC based coated graphite electrodes were fabricated using the ionophores N ‐((1 H ‐indol‐3‐yl)methylene)thiazol‐2‐amine (I 1 ), N ‐((1 H ‐indol‐3‐yl)methyl)‐thiazol‐2‐amine (I 2 ) and 1‐((1 H ‐indol‐3‐yl)methylene)urea (I 3 ). Their potentiometric performance was examined in dependence of the addition of plasticizers and anion excluders and compared. It is found that the coated graphite electrode with the composition I 1 :KTpClPB: o ‐NPOE:PVC=9 : 1.5 : 51 : 38.5 is the best with respect to the wide working concentration range (4.2×10 −8 –1.0×10 −1 mol L −1 ), low detection limit (1.6×10 −8 mol L −1 ) and wide pH range of 3.0–8.0. The proposed electrode was successfully applied to quantify Zn 2+ in various environmental, biological and medicinal plant samples and used as indicator electrode.