title: Potentiometric detection of mercury(II) ions using a carbon paste electrode modified with substituted thiourea-functionalized highly ordered nanoporous silica.
abstract: A potentiometric sensor is reported for the mercury(II) detection, which uses substituted thiourea-functionalized nanoporous silica (FTU-LUS-1) as the sensitive material. Substituted thiourea (FTU) and FTU-LUS-1 were first prepared and then characterized by 1H NMR, 19F NMR, 13C NMR, FTIR, XRD, TG and CNS elemental analysis. The electrodes with FTU-LUS-1 proportion of 10.0 wt% demonstrated very stable potentials. The prepared electrodes exhibit a Nernstian slope of 28.4 +/- 1.0 mV decade(-1) for mercury(II) ion over a wide concentration range of 1.0 x 10(-7) to 1.0 x 10(-1) mol dm(-3). The electrode exhibited a detection limit of 7.0 x 10(-8) mol dm(-3). Moreover, the selectivity coefficient, response time, performance, sensitivity and stability of the modified electrode were investigated. The electrode presented a response time of about 35 s, a high performance and sensitivity in a wide range of cation activities as well as good long term stability (more than 9 months). The method was satisfactory and could also be used to monitor the mercury(II) ion concentration in waste water and fish samples.
authors.affiliation: Department of Chemistry, Amirkabir University of Technology, Tehran, Iran. javanbakht@aut.ac.ir
authors.forename: Mehran
authors.initials: M
authors.lastname: Javanbakht
authors.forename: Faten
authors.initials: F
authors.lastname: Divsar
authors.forename: Alireza
authors.initials: A
authors.lastname: Badiei
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Ganjali
authors.forename: Parviz
authors.initials: P
authors.lastname: Norouzi
authors.forename: Ghodsi
authors.initials: G
authors.lastname: Mohammadi Ziarani
authors.forename: Marzieh
authors.initials: M
authors.lastname: Chaloosi
authors.forename: Ali
authors.initials: A
authors.lastname: Abdi Jahangir
mesh_terms: D002244:Carbon / Q000737:chemistry*; D004566:Electrodes; D007477:Ions / Q000032:analysis; D008628:Mercury / Q000032:analysis* / Q000737:chemistry; D015394:Molecular Structure; D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D016062:Porosity; D011199:Potentiometry; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties; D013890:Thiourea / Q000737:chemistry*
chemical_list: D007477:Ions; D002244:Carbon; D012822:Silicon Dioxide; D008628:Mercury; D013890:Thiourea