http://nopr.niscair.res.in/handle/123456789/1 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/18283 Title: Fluoride estimations in water using ion selective electrode: Choice of appropriate TISAB <br/> <br/>Authors: Agarwal, Meetu; Rai, Kavita; Shrivastav, Rohit; Dass, Sahab <br/> <br/>Abstract: Choice of appropriate TISAB (total ionic strength adjusting buffer) plays a crucial role in fluoride (F¯) analysis in water samples by ion selective electrode. Despite this no guideline is, yet, available on the choice of appropri ate TISAB for F¯ analysis in samples, particularly in presence of other ionic and non-ionic species. In this study, the efficacy of ten different TISABs for fluoride estimati on in water samples in presence of F¯ binding cations, viz. A1³⁺ and Fe³⁺ has been investigated. The study suggests that the TISA B, containing <i>tris</i>- hydroxymethyl aminomethane hydrochloride buffer is probably best suited for F¯ estimation in samples, especially, in presence of high concentrations (1-2 g dm^-3) of Al³⁺. <br/> <br/>Page(s): 999-1002 http://nopr.niscair.res.in/handle/123456789/18282 Title: Liquid-liquid extraction of tin (IV) with Cyanex 302 <br/> <br/>Authors: Sarkar, Sunil G; Dhadke, Purushottam M <br/> <br/>Abstract: A method for liquid-liquid extraction of Sn(IV) has been proposed. Tin (IV) is extracted from hydrochloric acid solution of 0.25 mol dm^-3 with 5×10^-2 mol dm^-3 Cyanex-302 in toluene, followed by spectrophotometric determination of Sn(IV) after stripping the non-aqueous phase with 4.0 mol dm^-3&nbsp; perchloric acid by Morin method. The optimum extraction conditions have been evaluated by studying parameters like acidity, extractant concentration, period of equilibrium, effect of diluents and effect of diverse ions. The method has been applied for the determination of Sn (IV) in real samples. <br/> <br/>Page(s): 996-998 http://nopr.niscair.res.in/handle/123456789/18281 Title: Preconcentration and determination of trace amounts of heavy metals in natural water samples using a C₁₈ cartridge and atomic absorption spectrometry <br/> <br/>Authors: Yamini, Y; Ebrahimzadeh, H; Chaloosi, M <br/> <br/>Abstract: A rapid and reliable sample preconcentration method has been developed to separate Ni²⁺, Bi ³⁺, Cd²⁺, Fe³⁺, Pb²⁺, Zn²⁺, Cu²⁺ and Co^2<i>+</i><i> </i>(heavy metal ions) from natural water samples. The<i> </i>chelating agent sodium diethyldithiocarbamate (SDDTC) and a C_l8 cartridge have been used for preconcentration. Extraction efficiency, influence of sample and eluent flow rates, <i>p</i>H, amount of SDDTC, nature and amount of eluent for elution of metal ions from cartridge, break through volume and the limit of detection have been evaluated. The effects of alkali and alkaline earth metal ions on percent recovery of heavy metal ions have also been studied. The limit of detection of the proposed method for Ni²⁺, Bi²⁺, Cd²⁺, Fe³⁺, Pb²⁺, Zn²⁺, Cu²⁺ and Co^2<i>+</i><i> </i>are found to be 1.5, 5, 0.4,3,2.5, 0.6, 0.5  and 1 ppb, respectively. The method is applied to the recovery and determination of heavy metal ions in different water samples. <br/> <br/>Page(s): 991-995 http://nopr.niscair.res.in/handle/123456789/18280 Title: Rapid spectrophotometric determination of platinum (IV) using piperonal thiosemicarbazone <br/> <br/>Authors: Shetty, Prakash; Shetty, A Nityananda; Gadag, R V <br/> <br/>Abstract: 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 <i>M </i>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 × 10⁴ l mol^-1 cm^-1 and 0.006 μg 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. <br/> <br/>Page(s): 988-990