http://nopr.niscair.res.in/handle/123456789/1447 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/1464 Title: A simple and sensitive method for determination of carbon disulphide in environmental and biological samples <br/> <br/>Authors: Tamrakar, Urmila; Gupta, V K; Mathewa, Sunitha B; Pillai, Ajai K <br/> <br/>Abstract: An analytical method using potassium dichromate and diphenylcarbazide for determination of carbon disulphide has been proposed. In this method carbon disulphide reduces the Cr(VI) to Cr(III) and the unreduced Cr(VI) forms a pink-purple complex with diphenylcarbazide in acidic medium, which is measured spectrophotometrically at 530 nm. Beer’s law is obeyed over a concentration range of 0.01 to 0.1 µg mL⁻¹. Molar absorptivity and Sandell's sensitivity were found to be 5.5 × 10⁵ L mol⁻¹ cm⁻¹ and 0.00013 µg cm⁻² respectively. The optimum reaction conditions and other analytical parameters were evaluated. The effect of interfering ions on the determination of CS₂ was studied. The method has been successfully applied for the determination of CS₂ in grain samples, fungicides (ziram, thiram) and various environmental and biological samples. <br/> <br/>Page(s): 306-309 Mon, 28 Apr 2008 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/1463 Title: Trace level extraction and spectrophotometric determination of cyanide in waste water and biological fluid <br/> <br/>Authors: Ansari, Anjum Ansari; Amlathe, Sulbha; Gupta, V K <br/> <br/>Abstract: An extractive spectrophotometric method for the determination of cyanide in wastewater is developed. Cyanide is reacted with bromine to form cyanogen bromide, which subsequently reacts with pyridine. Glutaconic aldehyde is formed through the heterolytic cleavage of pyridine ring, which is then coupled with 4-amino salicylic acid. A yellow orange dye formed in alkaline medium is extractable in n-butanol in acidic medium. The extract shows absorbance maxima at 520 nm. The system obeys Beer’s law in the range of 0.03-0.20 μg/mL. Important analytical parameters such as time, temperature, reagent concentration, acidity etc. have been optimized for complete colour reaction. Sandell’s sensitivity and molar absorptivity for the system have been calculated. The method has been successfully applied for determination of cyanide in wastewater and biological fluid. <br/> <br/>Page(s): 301-305 Mon, 28 Apr 2008 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/1462 Title: A comparative study of catalytic activity of tin phosphate and tin phenyl phosphonate <br/> <br/>Authors: P G, Chithra; B, Beena <br/> <br/>Abstract: Amorphous ion exchangers tin(IV) phosphate and tin(IV) phenyl phosphonate have been prepared and characterized. Catalytic activity has been studied and compared by using esterification of ethylene glycol as a model reaction wherein glycol diacetate has been prepared. The materials indicate good potential for Bronsted acid catalysis for the above reaction. <br/> <br/>Page(s): 298-300 Mon, 28 Apr 2008 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/1461 Title: Rapid extraction and separation of indium(III) with a high molecular weight amine <br/> <br/>Authors: Shilmkar, T N; Kolekar, S S; Wadgaonkar, P P; Anuse, M A <br/> <br/>Abstract: The liquid-liquid extraction of indium(III) from sodium succinate media using n-octylaniline in toluene as an extractant was studied. Quantitative extraction of indium(III) was observed in the range of 0.004-0.0075 M sodium succinate at pH 3.8-6.0 with 4% n-octylaniline in toluene. Indium(III) was completely stripped from the metal loaded organic phase of the extractant with water and determined complexometrically. The stoichiometry of the extracted species was determined on the basis of slope analysis. The extraction was found to proceed by a ion-pair mechanism with the extracted species being [RNH₃⁺In(succinate)₂‾]org.Separation of indium(III) was carried out from some associated metals like Tl(I), Mg(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), Pb(II), Ge(IV), Sb(III), Bi(III). The selectivity of the extraction of indium(III) can also be achieved by use of a suitable masking agent for estimation and determination from the synthetic mixture corresponding to alloy to show the practical utility of the extractant. <br/> <br/>Page(s): 291-297 Mon, 28 Apr 2008 22:58:59 GMT