1. Faculty Publications
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Item Spectrophotometric determination of palladium(II) using piperonal thiosemicarbazone(2003) Shetty, P.; Nityananda, Shetty, A.; Gadag, R.V.A simple, rapid, selective and sensitive spectrophotometric method for the determination of palladium is proposed using piperonal thiosemicarbazone (PATS) as a reagent. The reagent forms a 1:2 complex (Pd:Reagent) with palladium. The yellow complex is soluble in 32-40% ethanol and has an absorption maximum at 363 nm. Beer's law is obeyed upto 3.85 ppm of palladium and the optimum concentration range is 0.5-2.45 ppm of Pd. The molar absorptivity and Sandell's sensitivity are 3. 80 x 104 dm3 mol-1 cm -1 and 2.8 x 10-3 ?g cm-2, respectively. The experimental conditions for complete colour development and the interference from various ions are investigated. The method is used for the determination of palladium in its complexes and synthetic mixtures.Item Thioacetamide as a releasing agent for the complexometric determination of thallium(iii) in its synthetic alloys and complexes(2007) Karthikeyan, J.; Parameshwara, P.; Nityananda, Shetty, A.; Shetty, P.A simple and selective complexometric method for the determination of thallium is proposed, based on the masking ability of thioacetamide towards thallium(III). Thallium present in a given sample solution is first complexed with a known excess of EDTA and the surplus EDTA is titrated with standard zinc sulphate solution at pH 5-6 (hexamine buffer) using xylenol orange as the indicator. A 0.8% aqueous solution of thioacetamide is then added to displace EDTA from the TI(III)-EDTA complex. The released EDTA is titrated with standard zinc sulphate solution as before. Reproducible and accurate results are obtained for 0.018 - 0.371 mol L-1(3.79mg - 75.91mg) of Tl(III) with relative error less than 0.43% and coefficient of variation not more than 0.26%. The interference of various ions was studied and the method was used for the analysis of thallium in its synthetic alloy mixtures and also in complexes.Item The inhibition action of N-furfuryl-N?-phenyl thiourea on the corrosion of mild steel in acid media(2006) Shetty, S.D.; Shetty, P.; Nayak, H.V.S.The inhibiting effect of N-furfuryl-N?-phenyl thiourea (FPTU) on the corrosion of mild steel in aqueous solutions of 0.05 and 0.1MHCl, as well as 0.025 and 0.05 M H2SO4 has been demonstrated using the potentiodynamic polarization technique. The polarization data showed that FPTU acts as an efficient anodic inhibitor for mild steel in both acid solutions. Avery high inhibition efficiency was evidenced in both acid solutions and it was found to vary with the concentration of the inhibitor and temperature. The obtained kinetic parameters of adsorption revealed spontaneous adsorption and a strong interaction of FPTU with the mild steel surface.Item Sodium dithionite as a selective demasking agent for the complexometric determination of thallium(2005) Shetty, P.; Shetty, A.N.Sodium dithionite is proposed as a new demasking agent for the rapid and selective complexometric determination of thallium(III). In the presence of diverse metal ions, thallium (III) was first complexed with excess EDTA and the surplus EDTA was then titrated with a standard zinc sulphate solution at pH 5-6 (hexamine buffer) using Xylenol Orange as the indicator. The EDTA equivalent to thallium was then released selectively with sodium dithionite and back titrated with a standard zinc sulphate solution as before. Reproducible and accurate results were obtained in the range 4 - 100 mg of thallium with a relative error of 27 % and a coefficient of variation (n = 6) of not more than 0.30 %. The effects of various diverse ions were studied. The method was applied to the determination of thallium in its complexes and in alloys.Item Selective complexometric determination of palladium with sodium metabisulphite as releasing agent(2009) Shetty, P.; Shetty, A.N.Sodium metabisulphite has been proposed as a selective releasing agent for the rapid and selective complexometric determination of palladium. Pd(II) present in a given sample solution is first complexed with excess of EDTA and the surplus EDTA is back titrated with standard zinc sulphate solution at pH 5-5.5 (acetic acid-sodium acetate buffer) using xylenol orange as indicator. Sodium metabisulphite solution is then added to displace EDTA quantitatively from the Pd-EDTA complex. The released EDTA is back titrated with standard zinc sulphate solution as before. The method works well in the concentration range 2-20 mg of Pd with a relative error ? 0.40% and relative standard deviation ? 0.65%. The method has been applied to the determination of palladium in catalysts, alloys and complexes.Item Regioselective reaction: Synthesis, characterization and pharmacological studies of some new Mannich bases derived from 1,2,4-triazoles(2009) Isloor, A.M.; Kalluraya, B.; Shetty, P.In the present investigation, a series of new 4[(3-substituted-1H-pyrazol-4-yl)methyleneamino]-5-substituted-2-[(4-methylpiperzine-1-yl)methyl]-2H-1,2,4-triazole-3(4H)-thiones (4) were synthesized by the aminomethylation of 4-(3-substituted-1H-pyrazol-3-yl)methyleneamino-5-substituted-4H-1,2,4-triazole-3-thiols (3) with formaldehyde and N-methylpiperzine. These newly synthesized Schiff and Mannich bases were characterized by IR, 1H NMR, mass spectral data and elemental analyses. These compounds were screened for their antibacterial and antifungal activity. Some of the compounds were found to exhibit significant antimicrobial activity. 2009 Elsevier Masson SAS. All rights reserved.Item Redetermination of methyl 3,4-O-isopropyl-idene-?-D-fucopyran-oside monohydrate(2009) Fun, H.-K.; Jebas, S.R.; Rai, S.; Shetty, P.; Isloor, A.M.In the title compound, C10H18O5 H2O, the fucopyran-oside ring adopts a chair conformation. The crystal packing is stabilized by inter-molecular O - H?O and C - H?O hydrogen bonds together with intra-molecular O?O [2.2936 (8) ] and inter-molecular O?O [2.7140 (8)-2.829 (3) ] short contacts. The mol-ecules are linked together to form an infinite chain along the a axis. This structure has been solved previously but with no R-values [Spiers (1931). Z. Kristallogr. Kristallgeom. Kristallphys. Kristallchem. 78, 101].Item Rapid spectrophotometric determination of platinum (IV) using piperonal thiosemicarbazone(2002) Shetty, P.; Shetty, A.N.; Gadag, R.V.A simple, rapid, selective and sensitive spectrophotometric method for the determination of platinum has been proposed based on the colour reaction between platinum(IV) and piperonal thiosemicarbazone (PATS) in 0.008 - 0. 032 M sulphuric acid medium. The greenish yellow complex has an absorption maximum at 360 nm. Beer's law is obeyed upto 6.5 ppm of Pt and the optimum concentration range is 1 - 5.1 ppm of Pt. The molar absorptivity and Sandell's sensitivity are 3. 239 x 104 1 mol-1 cm-1 and 0.006 ?g cm-2, respectively. The optimum conditions for complete colour development have been investigated by studying parameters like effect of medium, acidity, reagent concentration, time period and effect of diverse ions. The method is used for the determination of platinum in hydrogenation catalysts and platinum complexes.Item Rapid complexometric determination of mercury(II) using glutathione as a selective demasking reagent(2004) Shetty, P.; Shetty, A.N.A simple, rapid and selective complexometric method is proposed for the determination of mercury(II) in the presence of associated metal ions. Mercury(II) is first complexed with an excess of EDTA and the surplus EDTA is titrated against standard zinc sulphate solution at pH 5-6 using xylenol orange indicator. Glutathione is then added to displace EDTA from the Hg-EDTA complex quantitatively and the EDTA released is back titrated against a standard zinc sulphate solution as before. The method works well in the range 4 to 80 mg of mercury with a relative error of less than 0.30% and a coefficient of variation of not more than 0.38%. The effect of the presence of various diverse ions has been studied. The method is used for the determination of mercury(II) in its alloys and complexes.Item Quantitative complexometric determination of palladium(II) in its synthetic alloys, complexes and catalysts using 2-mercaptopropionic acid as a selective masking agent(2007) Karthikeyan, J.; Parameshwara, P.; Nityananda, Shetty, A.; Shetty, P.A simple, rapid and accurate complexometric method for the determination of palladium(II) is proposed, based on the selective masking property of 2-mercaptopropionic acid towards palladium(II). In the presence of diverse metal ions, palladium(II) is complexed with excess of EDTA and the surplus EDTA is backtitrated with standard zinc sulphate solution at pH 5-5.5 (acetic acid-sodium acetate buffer) using xylenol orange as indicator. An excess of a 0.5% aqueous solution of 2-MPA is then added to displace EDTA from Pd(II)-EDTA complex. The released EDTA is titrated with the same standard zinc sulphate solution as before. Reproducible and accurate results are obtained in the concentration range 0.5-17.80 mg of palladium with relative error of 0.50% and coefficient of variation not exceeding 0.33%. The effects of diverse ions are studied. The method is used for the determination of palladium in its complexes, catalysts and synthetic alloy mixtures.