http://nopr.niscpr.res.in/handle/123456789/18285 2026-10-10T21:40:15Z http://nopr.niscpr.res.in/handle/123456789/18322 Title: Bismuth selective antimony(III) silicate inorganic ion-exchanger Authors: Reetha, C; Aravindakshan, K K; Janardanan, C Abstract: Antimony(III) silicate has been synthesised, characterised, and its ion exchange properties have been ascertained. The exchanger is stable in water, alcohol, acetic acid, 1.0M HCI, 1.0M HNO₃ and in aqueous solutions of LiCl, KCl MgCl₂, CaCl₂ and BaCl₂. Its exchange capacities for various alkali and alkaline earth metal ions have been determined. Also distribution coefficients for various metal ions, effect of electrolyte concentration and temperature and <i>p</i>H on ion exchange capacity have been studied. The molar ratio, found from chemical analysist as 1:1, suggests Sb₂O₃ 2SiO₂ nH₂O as the empirical formula for the exchanger. Binary separations of Bi(III) from Pb(II), Cu(II), Zn(II) and Hg(II) have been achieved from a column of the exchanger. Page(s): 1438-1440 2002-07-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/18321 Title: Spectrophotometric determination of iron in trace amount using 5-bromo-salicylaldehyde thiosemicarbazone Authors: Ramanjaneyulu, G; Reddy, P Raveendra; Reddy, V Krishna; Reddy, T Sreenivasulu Abstract: A simple, sensitive and specific spectrophotometric method has been developed for the determination of iron(II) in aqueous dimethylformamide (DMF). The metal ion reacts with 5- bromosalicylaldehyde thiosemicarbazone (5-BSAT) forming a green coloured complex in the <i>p</i>H<i> </i>range 5.0-6.0. The complex shows maximum absorption at 385 nm. Beer's law is obeyed in the range 0.28-5.60 μg/ml. The molar absorptivity and Sandell's sensitivity are found to be 1.72×10⁴l mol^-1 cm^-1 and 0.032 μg cm^-2, respectively. The method has been employed successfully for the determination of Fe(II) in grape leaves, multivitamin capsules and human blood. Page(s): 1436-1437 2002-07-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/18320 Title: Determination of zinc in high purity gallium by differential pulse anodic stripping voltammetry Authors: Sounderajan, Suvama; Singh, Avanti; Palrecha, M M Abstract: A simple voltammetric method has been described for the determination of trace amount of zinc in high purity gallium metal. Differential pulse anodic stripping voltammetry (DPASV), permits a direct determination of zinc without preliminary enrichment or separation process. Zinc can be determined to levels of 1-2 μg g^-l, with relative standard deviation of about 14% in  150 mg sample of gallium .The detection limit was restricted by the amount of zinc present in the reagent blank solution. The possible interferences due to Pb, Cd, Cu, Ni, Mn, Fe, Tl , Co, Ti, V. Al etc have also been evaluated. Page(s): 1433-1435 2002-07-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/18319 Title: Stability studies on 12-(5'-8'-hydroxyquinolinic)methylene-1,4,7,10- tetraazacyclo tridecane-11,13-dione, 5- substituted 1,10-phenanthroline-copper(II) with Cu²⁺ or Co²⁺ binuclear mixed coordinated systems Authors: Zhao, Xiaojun; Su, Xuncheng; Yang, Encui; Lin, Huakuan; Zhu, Shourong; Sun, Hongwei; Chen, Yunti Abstract: C-functionalized dioxotetraamine ligands L have been designed and synthesized through simple methods, and characterized by elemental analysis, IR, mass spectra and ¹H NMR. The ligand contains two independent chelating groups. At 25.0±0.1^oC, I=0.1 mol·dm^-3 NaNO₃, <i>p</i>H titration has been performed to study the stability properties of L-5-R-5,10-phenanthroline-Cu(II) with proton, copper(II) and cobalt(II). The ternary complexes have been shown to possess interesting properties due to the involvement of three chelating groups, 5-substituted- 1, 10-phenanthroline, 8- hydroxyquinoline and dioxotetraamine. In addition, potentiometric titrations have been performed to study the protonation of L-5-R- 1, 10-phenanthroline-Cu(II) (R=CH₃,H,Cl,NO₂) and their stability properties with copper(II) and cobalt(II). The results show that for Cu²⁺ and Co²⁺, 8-hydroxyquinoline is a strong chelating reagent than dioxytetraamine macrocycles. Using molecular mechanics (MM⁺) calculation, the stability of ternary mixed system on Co(II)L- S-substituted- 1, 10-phenanthroline-Cu(II) and Cu(II)-L-Ssubstituted-1, 10-phenanthroline-Cu(II) have been studied and compared with the coordination ability for different coordination sites and for different metal ions (Co(II) and Cu(II) at the same coordination site. The results obtained from calculation agree with the experimental results. Page(s): 1428-1432 2002-07-01T00:00:00Z