Authors: Lidiya N. Skvortsova, Aleksey S. Podprugin, Vladimir I. Otmakhov
Abstract: Tiron has been proposed for the removal of Fe (III) and Mg (II) ions from the test solution by ion exchange in the REE trace analysis in rocks by ICP-MS. The conditions for Fe (III) isolation on a column with anion-exchange resin АВ-17-8,Cl– and for Mg (II) on a column with cation-exchange resin Purolite С100 have been found. The concentration of Fe (III) is reduced up to 10 times, and Mg (II) – more than 100 times. Correction factors have been used in order to eliminate the systematic error in the determination of REE due to their partial sorption on the anion-exchange resin in the form of complexes with Tiron. The correctness and accuracy of the developed sample preparation method and of the correction factors have been confirmed in the analysis of standard samples base on natural geochemical objects.
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Authors: Chang Qing Tu, Xin Rong Wen
Abstract: Fe (Ш) can be reduced to Fe (II) by hydrosulfuryl (-SH) in acetylcysteine molecule,and then using tiron as chromogenic reagent of Fe (Ш),and the content of acetylcysteine is determinated indirectly through determinating the surplus content of Fe (Ш) in the system.An accurate fast spectrophotometric method for the determination of acetylcysteine by discoloration spectrophotometry using Fe (Ш)-tiron system has been established.This proposed method had been successfully applied to determinate of acetylcysteine in real pharmaceutical.
2710
Authors: Chang Qing Tu, Xin Rong Wen
Abstract: A novel method for the indirect determination of methimazole by discoloration spectrophotometry using Fe (Ш)-tiron system has been established.The various effect factors on the determination of methimazole by discoloration spectrophotometry using tiron-Fe (Ш) system were investigated in detail. The results showed that by controlling pH=2.8,Fe (Ш) could be reduced to Fe (II) by hydrosulfuryl (-SH) in methimazole molecule,and then using tiron as chromogenic reagent of Fe (Ш),and the content of methimazole was determinated indirectly through determinating the surplus content of Fe (Ш) in the system.The maximum absorption wavelength of chromogenic system was 663 nm, good linear relationship was obtained between A and the concentration of methimazole in the range of 3.2~12.8μg·mL-1,the equation of the linear regression was A=-0.1849+57.277ρ (mg·mL-1),with a linear correlation coefficient was 0.9998.This proposed method had been successfully applied to determinate of methimazole in real pharmaceutical.
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Authors: Yan Xu, Yue Hua Wen, Jie Cheng, Gao Ping Cao, Yu Sheng Yang
Abstract: Electrochemical oxidation of tiron in the presence of H2O as a nucleophile in strongly acidic aqueous solutions was studied by cyclic voltammetry, controlled-voltage coulometry and spectrometric investigations. The mechanism of electrochemical reaction is confirmed by spectrophotometric tracing in various times of controlled-voltage coulometry. The voltammetric and spectrophotometric foundations indicate that a 1,4-Michael addition of H2O from its hydroxy moiety to the position 4 of electrochemically derived o-quinone is occurred. The electrochemical oxidation and reduction of tiron has been successfully accomplished by controlled-voltage coulometry in a redox flow-through type cell and the final electro-reduced product was characterized by spectrophotometric, 1H NMR and mass spectrometric methods. It is demonstrated that the electro-oxidation of tiron follows an ECE mechanism in acidic aqueous solutions, leading to formation of a new compound of para- benzoquinone derivative.
1730
Authors: Yamini Asthana, Dong Pyo Kim
Abstract: Formation of coatings with combined properties of being superhydrophilic /
superhydrophobic is of immense applications in the field of optics. In our present work, we developed a hydrophilic, antifogging, transparent, and stable coating by employing an anionic electrolyte, Tiron and dip-coating of organic-inorganic mixture. One of the attempts was to adhere Tiron on metal oxide surface by chelating effect, and the other one was to apply an organicinorganic coating on glass or lens substrate. The latter was formulated by mixing appropriate ratios of organic silanol coupling agents and diacrylates component for strong adhesion to the
substrate, and inorganic component of a hybrid mixture of silica, titania and Tiron for the antifogging behavior. The surface chemistry of the coated films was studied by taking ATR-IR measurements, and the wetting behavior was characterised by contact angle measurement
42
Authors: J.J. Roćen, Lj.S. Čerović, S.K. Milonjić
Abstract: It has been shown recently that small organic molecules, used as dispersants in the
colloidal processing of ceramic powders to adjust the forces between the particles, are quite efficient in preparing aqueous suspensions of high solid loadings and low viscosity. One of them is 4,5-dihydroxy-1,3-benzenedisulfonic acid, disodium salt monohydrate, ((OH)2C6H2(SO3Na)2·H2O), commercially known as Tiron. The adsorption of Tiron, as a function of its concentration and solution pH, onto alumina was investigated by the solution depletion method, applying UV spectrophotometry. KNO3 (10-2 mol/l) was used as the background electrolyte. The obtained results indicate an increase in the amount of adsorbed Tiron with its increasing concentration. The maximum adsorption was recorded at pH≈7 when the Tiron molecule was uncharged, i.e. undissociated (pKa1=7.6). The experimental data were fitted with different adsorption isotherm models. The maximum amount of Tiron adsorbed, as well as the constants of adsorption process were calculated.
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