title: Mercury(II) ion-selective electrodes based on heterocyclic systems.
abstract: Mercury ion-selective electrodes (ISEs) were prepared with a polymeric membrane based on heterocyclic systems: 2-methylsulfanyl-4-(4-nitro-phenyl)-l-p-tolyl-1H-imidazole (I) and 2,4-diphenyl-l-p-tolyl-1H-imidazole (II) as the ionophores. Several ISEs were conditioned and tested for the selection of common ions. The electrodes based on these ionophores showed a good potentiometric response for Hg2+ ions over a wide concentration range of 5.0 x 10(5-) - 1.0 x 10(-1)M with near-Nernstian slopes. Stable potentiometric signals were obtained within a short time period of 20 s. The detection limits, the working pH range of the electrodes were 1.0 x 10(-5) M and 1.6-4.4 respectively. The electrodes showed better selectivity for Hg2+ ions over many of the alkali, alkaline-earth and heavy metal ions. Also sharp end points were obtained when these sensors were used as indicator electrodes for the potentiometric titration of Hg2+ ions with iodide ions.
authors.affiliation: Department of Chemistry, Guru Nanak Dev University, Amritsar-143005, India. rakesh_chem@yahoo.com
authors.forename: Rakesh Kumar
authors.initials: RK
authors.lastname: Mahajan
authors.forename: Pallavi
authors.initials: P
authors.lastname: Sood
authors.forename: Mohinder
authors.initials: M
authors.lastname: Pal Mahajan
authors.forename: Alka
authors.initials: A
authors.lastname: Marwaha
mesh_terms: D006571:Heterocyclic Compounds / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D017736:Ion-Selective Electrodes; D008628:Mercury / Q000032:analysis*; D012680:Sensitivity and Specificity
chemical_list: D006571:Heterocyclic Compounds; D008628:Mercury