NOPR Collection:

Spectrophotometric determination of thorium(IV) using 3-hydroxy-2-(2'-thienyl)-4H-chromen-4-one

Sun, 01 Sep 2002 00:00:00 GMT

Title: Spectrophotometric determination of thorium(IV) using 3-hydroxy-2-(2'-thienyl)-4H-chromen-4-one Authors: Garg, Amita; Kakkar, L R Abstract: A spectrophotometric method has been developed to determine thorium using 3-hydroxy-2-(2'-thienyl)-4H-chromen-4-one (HTC) which forms a 1:4 yellow complex in dilute acetic acid solution with λ_max at 430 nm. The method is free from the interference of a large number of metal ions of interest. Molar absorpti vity and Sandell's sensitivity of the complex are 3.95×10⁴ L mol^-1 cm^-1 and 0.0059 μg cm^-2 respectively. Page(s): 1874-1876

Spectrophotometric determination of trace amounts of tellurium based on its catalytic effect in the reduction of gallocyanine with sodium sulphide

Sun, 01 Sep 2002 00:00:00 GMT

Title: Spectrophotometric determination of trace amounts of tellurium based on its catalytic effect in the reduction of gallocyanine with sodium sulphide Authors: Ensafi, Ali A; Tehrany, M Saber; Keyvanfard, M Abstract: A simple and sensitive kinetic spectrophotometric method for the determination of ultra trace amounts of tellurium(IV) has been proposed. It is based on the catalytic effect of Te(IV) on the reduction of gallocyanine by sodium sulphide. The reaction is monitored spectrophotometrically by measuring the decrease in absorbance of the reaction mixture at 618 nm. The method allows the determination of tellurium concentration in the range 2.0-200 ng/ml, with the detection limit of 1 ng/ml. The relative standard deviation for ten replicate determinations of 20.0 and 50.0 ng/ml Te( IV) is 1.7% and 1.1 %, respectively. The method has been applied to determination of tellurium in water samples. Page(s): 1871-1873

Simultaneous detection of Anatoxin-a and Microcystin-LR from cyanobacterial strains using high-performance liquid chromatography and LC-ESI-MS method

Sun, 01 Sep 2002 00:00:00 GMT

Title: Simultaneous detection of Anatoxin-a and Microcystin-LR from cyanobacterial strains using high-performance liquid chromatography and LC-ESI-MS method Authors: Nivsarkar, Manisha; Acharya, Jyotiranjan; Rao, P V Lakshmana; Kaushik, M P Abstract: A method has been developed for the simultaneous extraction, purification and detection of cyanobacterial toxins (hepatotoxin and neurotoxin) from a single batch of Microcystis aeruginosa and Anabaena flos-aquae. After several ex tractions and ad sorption on to C- 18 sep-pak cartridge, the cyanobacterial tox ins have been detected both by high performance liquid chromatography and LC-ESI-mass spectrometry. Anatoxin-a and Microcystin –LR have been detected in UTEX-2383 and UTEX-2385 strains of Anabaena flos-aquae and Microcystis aeruginosa respectively. Page(s): 1867-1870

Synthesis, characterization and catalytic application of tin phosphate

Sun, 01 Sep 2002 00:00:00 GMT

Title: Synthesis, characterization and catalytic application of tin phosphate Authors: Patel, Sonal M; Chudasama, Uma V Abstract: Tin phosphate, a tetravalent metal acid salt, has been synthesized and characterized. The H⁺ ions contained in the structural hydroxyl groups of the tma salts are labile and hence the material can be used as a solid acid catalyst. Esterification reaction has been chosen as a model reaction and acetate esters of Ethyl, n –Propyl, n-butyl and benzyl alcohols have been prepared by varying the mole ratio of alcohol to acid and amount of catalyst. Page(s): 1864-1866