Publications (894) View all
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Article: Selective sensing of mercury(II) using PVC-based membranes incorporating recently synthesized 1,3-alternate thiacalix[4]crown ionophore.
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ABSTRACT: The construction and electrodes characteristics of poly(vinylchloride) (PVC)-based polymeric membrane electrode (PME) and coated graphite electrode (CGE), incorporating 1,3-alternate thiacalix[4]crown as ionophore for estimation of Hg(II) ions, are reported here. The best potential response was observed for PME-1 having membrane composition of: ionophore (6.2 mg), PVC (100.0 mg), 2-nitrophenyl octyl ether (2-NPOE; 200.0 mg), and sodium tetraphenyl borate (NaTPB; 2.0 mg); for CGE-1 with the membrane composition: ionophore (3.5 mg), PVC (40.0 mg), 2-NPOE (80.0 mg), and NaTPB (2.0 mg). The electrodes exhibits Nernstian slope of 29.16 mV/decade with PME-1 and 30.39 mV/decade with CGE-1 for Hg(II) ions over wide concentration range, i.e., 1.0 × 10(-1) to 5.0 × 10(-6) M with PME-1 and 1.0 × 10(-1) to 5.0 × 10(-7) M with CGE-1. Lower detection limits were found to be 9.77 × 10(-6) M for PME-1 and 7.76 × 10(-7) M for CGE-1 with response time varying from 10 to 20 s. Also, these electrodes work within pH range of 2.0-6.0 for PME-1 and 1.5-6.5 for CGE-1. Overall, CGE-1 has been found to be better than PME-1. CGE-1 has been used as indicator electrode for the potentiometric titration of Hg(II) ions with EDTA as well as successfully applied for determination of Hg(II) content in wastewater, insecticide, dental amalgam, and ayurvedic medicines samples with very good performance (0.9974 correlation coefficient in the comparison against volumetric method).Environmental Science and Pollution Research 10/2012; · 2.65 Impact Factor -
Article: Mercury(II) ion recognition by newly synthesized oxadiazaphosphepine based receptors: coated graphite and polymeric membrane electrodes
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ABSTRACT: Oxadiazaphosphepine based receptors were synthesised and their ion sensing properties have been investigated. Polymeric membrane electrodes (PMEs) and coated graphite electrodes (CGEs) based on these receptors exhibited selective response for mercury(II) ions and the response characteristics of CGEs were found to be comparatively better. 2,2,2,4,7-Pentaphenyl-5-o-tolyl-2,5-dihydro-2l5-[1,3,5,2]oxadiazaphosphepine based coated graphite electrode (CGE-1) exhibited Nernstian response (29.39mV/decade) for mercury(II) ions over a wide concentration range (1.0×10−1M–1.0×10−6M) with lower detection limit of 7.24×10−7M. The proposed electrodes possess high selectivity for mercury(II) ions with respect to alkali, alkaline and heavy metal ions especially silver(I) ions ( logK\textHg2 + ,\textAg + \textPot. = - 0.35 \log K_{{{\text{Hg}}^{2 + } ,{\text{Ag}}^{ + } }}^{{{\text{Pot}}.}} = - 0.35 ) and have wide functional pH range (0.95–4.50) with fast response time of less than 10s. These electrodes have been successfully used as indicator electrodes during the potentiometric titrations of mercury. KeywordsOxadiazaphosphepine derivatives–Mercury(II) ion selective electrodes–Coated graphite electrodes–Polymeric membrane electrodes–Potentiometric sensorsJournal of Inclusion Phenomena 04/2012; 69(1):263-271. · 1.89 Impact Factor -
Article: Highly effective chemosensor for mercury ions based on bispyrenyl derivative.
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ABSTRACT: A new bispyrenyl azadiene derivative has been synthesized and examined for its cation recognition abilities toward different cations. The ligand shows strong affinity for Hg(2+) ions over other cations such as Cu(2+), Pb(2+), Zn(2+), Ni(2+), Cd(2+), Ag(+), K(+), Na(+) and Li(+). An "Off-On" type of fluorescent behaviour was observed with simultaneous presence of Cu(2+) and Hg(2+) ions. An ion selective electrode (ISE) is also formed which showed excellent selectivity to Hg(2+) over all the other cations tested. The lower limit of detection is 7.08 x 10(-6) M.The Analyst 07/2010; 135(7):1600-5. · 4.23 Impact Factor -
Article: Highly selective potentiometric determination of mercury(II) ions using 1-furan-2-yl-4-(4-nitrophenyl)-2-phenyl-5H-imidazole-3-oxide based membrane electrodes.
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ABSTRACT: The electrode characteristics and selectivities of PVC-based mercury(II) selective coated graphite electrode (CGE) and polymeric membrane electrode (PME) incorporating the recently synthesized 1-furan-2-yl-4-(4-nitrophenyl)-2-phenyl-5H-imidazole-3-oxide are reported here. The electrodes exhibit Nernstian slope for mercury(II) ions over wide concentration ranges, i.e. 1.0 x 10(-1)M to 1.0 x 10(-6)M (with CGE) and 1.0 x 10(-1)M to 1.0 x 10(-5)M (with PME). The lower detection limits shown by CGE and PME are 8.91 x 10(-7)M and 6.30 x 10(-6)M, respectively, in the pH range of 1.0-4.0. From the comparative study of these electrodes, CGE has been found to be better than PME in terms of lower detection limit and better selectivity for mercury(II) ions with comparatively less interference from silver(I) ions. The proposed electrodes can be successfully used as an indicator electrode for potentiometric titration of mercury with potassium dichromate. The electrodes have been successfully applied for estimation of mercury content in synthetic water samples, insecticide (parad tablet) and dental amalgam.Journal of hazardous materials 01/2009; 167(1-3):237-43. · 4.14 Impact Factor -
Article: Investigation of Silver(I) Ion Sensing Property of Ruthenium(II) Thiosemicarbazone Complex Using Coated Graphite and Polymeric Membrane Electrodes
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ABSTRACT: A ruthenium(II) complex [Ru(PPh3)2(pytsc)2] {Hpytsc = pyridine-2-carbaldehydethiosemicarbazone, (C5H5N)C2(H)=N3-N2(H)-C1(=S)N1H} has been used as an ion carrier for the selective determination of silver(I) ions in solution. Silver(I) ion-selective coated graphite based (CGE) and PVC polymeric membrane based (PME) electrodes exhibit Nernstian slope for silver(I) ions over a wide concentration range from 1.0 × 10−1 M to 5.0 × 10−6 M (with CGE) and 1.0 × 10−1 M to 2.0 × 10−5 M (with PME). The working pH range of these electrodes has been found to be from 1.2 to 7.2 for CGE and 2.2 to 6.5 for PME. The proposed CGE sensor exhibits better analytical features like sensitivity and selectivity towards different secondary ions in comparison to the corresponding PME with no interference from mercury(II) ions . These electrodes also act as indicator electrodes in potentiometric titration and have been successfully used for the determination of silver content in solution of real samples (1 gm dissolved in 100 mL of dilute nitric acid) such as silver ornaments and thin silver foils. Silver content determined by the use of ion selective electrode was found to vary in the concentration range from 1.20 x 10−2 M to 7.45 x 10−2 M and results were found to be comparable with those obtained from the traditional volumetric method of analysis. It is the first report of a metal-ligand complex used as an ion carrier in ion selective electrode, which is selective for a metal ion other than the one used in the complex.Zeitschrift für anorganische Chemie 06/2008; 634(9):1626 - 1632.
