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Volumetric, Viscometric, and Refractive Index Studies of Some alfa-Amino Acids in Aqueous Tartrazine at Different Temperatures

Ali A., Patel R., Shahjahan, Tasneem S.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 7

1353-1363

EN

The densities (r), viscosities (h), and refractive indices (nD) of (0.10, 0.15, 0.20, 0.25, and 0.30) m glycine, L-alanine, and L-valine were measured in 0.01 m aqueous tartrazine at 288.15, 293.15, 298.15, 303.15, 308.15, and 313.15 K. The measured data were utilized to evaluate various use ful parame ters, viz., apparent molar volume, (fi ni ), partial molar volume, (fi ni o), partial molar isobaric expansibility, (fi i E o ), transfer volume (fi ni o (tr)), A and B – coefficients of viscosity, free energy of activation of viscous flow per mole of solvent (Delta mi 1 o*) and solute (Delta mi 2o*) and molar refractivity (RD). The linear varia ion of fi ni o with the number of carbon atoms (nC) present in the alkyl chain of amino acids was also considered for the evaluation of the contribution of zwitterionic end groups (NH3 + , COO–) and methylene groups to fi ni o. The results were used to discussion–ion, ion–nonpolar and nonpolar–nonpolar interactions and the presence of structural hydration in the present systems.

2

Hisslers observed during daytime in a low latitude ground station

Singh K., Patel R., Kumar B., Altaf M., Ganai P., Singh A., Singh R., Lalmani

Acta Geophysica

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2009

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Vol. 57, no. 2

536-547

EN

The observation of hisslers during daytime at low latitude station Jammu, India, is reported. The hissler elements are quasi-periodic falling tones observed during the period of hiss activity and appear in minutelong sequences with average spacing between individual elements of the order of 0.15 s. Hissler elements exhibit almost no dispersion and no complex internal structure in slope and intensity, and successive hissler elements do not overlap in time. It seems that the reported hisslers might have propagated in prolongitudinal mode.

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Flow-injection analysis determination of thiocyanate in industrial waste water

Patel R., Patel K. S.

Chemia Analityczna

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1999

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Vol. 44, No. 5

917-923

EN

A new, simple, fast and selective procedure for tlow-injection analysis (FIA), and reverse flow-injection analysis (RFIA) determinations of thiocyanate by reacting it with iron(III) ions is described. The value of apparent molar absorptivity of the complex in terms of thiocyanate in FIA and RFIA systems are 3.00 x 10(3) and 4,75x l 031 mol(-1) cm(-1), at Amax = 460 nm, respectively. The detection limits in the FIA and RFIA systems are found to be 90 and 120 ~g I-I SCN-, respectively at the gain factor 2. The sample throughput is 100 samples h (-1). The method is highly selective and reproducible for determination of thiocyanate in industrial waste waters.

PL

Opracowano nową, prostą, szybką i selektywną metodę wstrzykowej analizy przepły-wowej (FIA) i odwróconej wstrzykowej analizy przepływowej (RFIA) do oznaczania tiocyjanianów na podstawie reakcji z jonami żelaza(III). Wartości molowych współczynników absorpcji, w przeliczeniu na tiocyjaniany, wynoszą odpowiednio 3,O x 103 i 4,75 x 10(3) I mol (-1) cm (-1), dla FIA oraz RFIA przy długości fali 460 nm. Granica wykrywalności w układzie FIA i RFIA wynosi odpowiednio 90 i 120 ug I(-I), przy wzmocnieniu równym 2. Postępowanie umożliwia wykonanie 100 oznaczeń na godzinę. Metoda jest dobrze odtwarzalna przy oznaczaniu tiocyjanianów w ściekach przemysłowych.