Abstract
The electrode characteristics and selectivities of PVC-based perchlorate selective coated graphite electrode (CGE) and polymeric membrane electrode (PME) incorporating the synthesized zinc complexes of 6,7: 13,14-dibenzo-2,4,9,11-tetramethyl-1,5,8,12-tetraazacyclotetradecane-1,4,6,8,11,13 hexaene (I-1) and 6,7:13,14-dibenzo-2,4,9,11-tetramethyl-1,5,8,12-tetramethylacrylate-1,5,8,12-tetraazacyclotetradecane-6,13-diene (I-2) are reported here. Several membranes having different compositions of PVC, plasticizers, ionic additives and ionophores were fabricated and the best response was observed for the membrane having composition I-2:PVC:BA:HTAB in the ratio of 7:32:59:2 (w/w; mg). The response characteristics of PME based on the above mentioned membrane was also compared with CGE. The electrode exhibits a Nernstian response for perchlorate ions over wide concentration ranges i.e. 8.3 x 10(-7) to 1.0 x 10(-2) mol L-1 (with PME) and 1.0 x 10(-7) to 1.0 x 10(-2) mol L-1 (with CGE) and response time of 12 s and 9 s for PME and CGE, respectively. Furthermore, the electrodes generated constant potentials in the pH range of 3.0-8.0 for PME and 2.5-9.0 for CGE. The high selectivity of CGE for perchlorate ions permits its use in the determination of perchlorate ions in water and human urine samples. (C) 2014 Elsevier B.V. All rights reserved.