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السجلات المعروضة 11 -- 20 من 661
Selective determination of thiamine (vitamin B1) in pharmaceutical preparations by direct potentiometric argentometric titration with use of the silver-silver sulphide ion-selective electrode
(
Elsevier
, 1989 , Article)
A simple and selective argentometric titration method is described for determination of thiamine (vitamin B1), based on direct potentiometric titration in alkaline media (⩾0.5M) in which a chemical transformation takes ...
Liquid membrane electrodes for the selective determination of nicotine in cigarette smoke
(
The Royal Society of Chemistry
, 1989 , Article)
Five liquid membrane electrode systems responsive to the nicotinium cation are described. These electrodes are based on the use of the ion-association complexes of the nicotinium cation with tetraphenylborate, 5-nitrobarbiturate, ...
Thiamine-reineckate liquid membrane electrode for the selective determination of thiamine (vitamin B1) in pharmaceutical preparations
(
The Royal Society of Chemistry
, 1989 , Article)
The construction and electrochemical response characteristics of a liquid membrane electrode for thiamine (vitamin B1) based on the formation of an ion pair between the thiamine cation and the reineckate anion in nitrobenzene ...
Iridoids and flavonoids of Teucrium polium herb
(
Thieme
, 1986 , Article)
The iridoid glycoside teucardoside and the flavonoids salvigenin and cirsiliol have been isolated from Teucrium polium var. pilosum and T. polium var. alba. The medicinal significance of these findings is discussed.
Constituents of plants growing in Qatar III - Nutritive constituents of Garawah (Glossonema edule)
(
Junk Publishers
, 1983 , Article)
Both the pericarp and the unripe seeds of the unripe fruits of Glossonema edule were separately analysed. The crude protein content of the unripe seeds is double that of the pericarp. Investigation of the amino acids of ...
Constituents of plant growing in Qatar. II. Investigation of Euphorbia granulata
(1982 , Article)
N/A.
Far-infrared and Raman spectroscopic studies of polyiodides
(
American Chemical Society
, 1986 , Article)
The far-infrared and Raman spectra of (CH3)4NI5, (TMA.H2O)10HI5 (TMA = trimesic acid), (phen)2HI5 (phen = phenacetin), (CH3)4NBrI4, (C2H5)4NI7, and (CH3)4NI9 have been recorded and analyzed. The first three compounds contain ...
Spectroscopic studies of nickel and iron clusters at 12 K
(
AIP Publishing
, 1987 , Article)
The electronic and far‐infrared spectra of nickel and iron clusters trapped in argon matrices at 12 K are reported. The ν3 antisymmetric stretching frequencies for Ni3 and Fe3 were observed for the first time at 198 and ...
Infrared and Raman studies of [UO2(salen)(L)] (L=H2O and CH3OH)
(
Elsevier
, 1988 , Article)
The infrared and Raman spectra of [UO2(salen)(H2O)] and [UO2(salen)(CH3OH)] (salen=N,N′-ethylenebis(salicylideneimine) have been recorded. Assignments for the fundamental vibrations are proposed on the basis of C2v symmetry ...
Electronic spectral studies and solvent effects on the reaction of iodine with 1,4,8,11-tetraazacyclotetradecane
(
Elsevier
, 1988 , Article)
The reaction between iodine and 1,4,8,11-tetraazacyclotetradecane (TACTD) is studied photometrically in various solvents like CCl4, CHCl3, CH2Cl2 and 1,2-dichloroethane. The results reveal that in each solvent the (TACTD):I2 ...