scholarly journals Composition, stability and stereo effects of zirconium(IV) dl-tartrate formation

2019 ◽  
Vol 57 (2) ◽  
pp. 28-34
Author(s):  
Lilia I. Mukhamedyarova ◽  
◽  
Sergey G. Bezryadin ◽  
Elena Yu. Klukvina ◽  
Vladimir V. Chevela ◽  
...  
Keyword(s):  
Tartaric Acid ◽  
Ph Value ◽  
Acid System ◽  
Alkaline Ph ◽  
Titration Method ◽  
Software Complex ◽  
Tartaric Acids ◽  
Potentiometric Titration Method ◽  
High Concentrations ◽  
Metal Ligand

The system of zirconium (IV) – dl-tartaric acid for metal: ligand 1: 1, 1: 2 and 1: 3 ratios in aqueous solution has been studied by means of using potentiometric titration method in combination with mathematical modeling. The comparison of Bjerrum functions from pH for zirconium(IV) systems: d-tartaric acid and zirconium (IV): dl-tartaric acid, has revealed the following features in the behavior of the curves: the degree of titration for the complexes at a fixed pH value for systems with dl-tartaric acid is more than for d-acid. The CPESSP software complex has calculated the composition, stability constants and molar fractions of zirconium(IV) tartrate accumulation. It has been also found that at a ratio of 1: 1 for Zr (IV) and ligand (H4Tart) ions in the system under study ZrHTart+ is formed, which is tetramerized into Zr4Tart40 and, further, tetranuclear particles of varying degrees of deprotonization are formed, as well as mononuclear forms. In a strongly alkaline pH environment > 10, Bjerrum curves for d- and dl-tartaric acids overlap each other and correspond to hydroxocomplexes of varying degrees of titration. For the 1: 2 ratio, the composition of the complexes for the zirconium(IV) – dl-H4T system is slightly different; compared to the zirconium(IV) – dH4T system, differences are clearly observed for both low and high concentrations. Based on these data, a complex formation scheme in the Zr(IV) – dl-tartaric acid system has been proposed for all the ratios studied. The characteristics of stereoselective diastereomer formation have been calculated. It has been revealed that in the medium of racemic tartrate, ddd- and lll-Zr(H2Tart)2(HTart)3-forms, as well as Zr(H2Tart)(НTart)24-Zr(HTart)35- are formed on a stereoselective basis.

scholarly journals Stability of zirconia sol in the presence of various inorganic electrolytes

2013 ◽  
Vol 78 (12) ◽  
pp. 1975-1982 ◽  
Author(s):  
Jelena Markovic ◽  
Slobodan Milonjic ◽  
Vukadin Leovac
Keyword(s):  
Experimental Error ◽  
Ph Value ◽  
Critical Concentration ◽  
Zirconium Oxychloride ◽  
Critical Coagulation Concentration ◽  
Titration Method ◽  
Potentiometric Titration Method ◽  
Forced Hydrolysis ◽  
The Stability ◽  
Hydrated Zirconia

Zirconia sol was prepared from zirconium oxychloride solutions by forced hydrolysis at 102?C. The prepared sol consisted of almost spherical, monoclinic, hydrated zirconia particles 61 nm in diameter. The stability of zirconia sol in the presence of various inorganic electrolytes (LiCl, NaCl, KCl, CsCl, KBr, KI, KNO3, and K2SO4) was studied by potentiometric titration method. Dependence of the critical concentration of coagulation (CCC) on the dispersion pH was determined for all studied electrolytes. The critical coagulation concentration values, for all investigated electrolytes, are lower at higher pH. These values for all 1:1 electrolytes are equal in the range of experimental error. For a given pH value, CCCs of K2SO4 are 3-4 orders of magnitude lower than the corresponding values for 1:1 electrolytes.

scholarly journals Effervescent Tablet Formulation Melinjo Seed Extract (Gnetum gnemon L.) Using PEG 6000 As Lubricant and Citric Acid - Tartaric Acids As Acid Sources

2018 ◽  
Vol 18 (1) ◽  
pp. 30-41
Author(s):  
Puput Andi Apsari ◽  
Dewi Nur Eka Sari ◽  
Aris Perdana Kusuma ◽  
Oktavia Indrati
Keyword(s):  
Citric Acid ◽  
Tartaric Acid ◽  
Antioxidant Properties ◽  
Seed Extract ◽  
Pharmaceutical Dosage Form ◽  
Peg 6000 ◽  
Tartaric Acids ◽  
Weight Variation ◽  
High Concentrations ◽  
Effervescent Tablet

Melinjo seeds (Gnetum gnemon L.) have antioxidant properties one of which is from phenol compounds. However, there is no pharmaceutical dosage form of melinjo seeds especially effervescent tablet. The purpose of this research was to determine the best variation of citric-tartaric acid and PEG 6000 from effervescent tablet of melinjo seed extract. The effervescent tablet of melinjo seed extract were formulated with variation of citric-tartaric acid 25%:75%, 65%:35%, 50%:50%, 20%:80% and PEG 6000 0%, 2%, 3%, up to 5%. The effervescent tablet were made by melting parts of acids and bases, added with extract and other ingredients. The evaluation included flow and powder tapping, tablet hardness, weight variation, friability, and tablet solubility test. The data were analyzed by comparing approaches based on the requirements of Pharmacopeia Indonesia V andUnited States of Pharmacopeia 36.Variations of equal amount of citric-tartaric acid produced hard effervescent tablets with small friability. The unbalanced acid concentration resulted in higher friability. The greater the concentration of citric acid resulted in the longer solubility of the tablet. The addition of PEG 6000 made the flow time of granules quicker, while higher concentrations would increase the hardness of tablets and accelerate the soluble time. Excessively high concentrations resulted in a high degree of friability. Variation of citric-tartaric acid and PEG 6000 influenced physical properties of granule and effervescent tablet extract of melinjo seeds, such as flowability, hardness, friability, and solubility of the tablet.

Enzymatic Iodination of Maleic and Fumaric Acids Diethyl Esters

2009 ◽  
Vol 59 (12) ◽  
pp. 1400-1404
Author(s):  
Marius Tudorascu ◽  
Spiridon Oprea ◽  
Afrodita Doina Marculescu ◽  
Stefania Tudorascu
Keyword(s):  
Hydrogen Peroxide ◽  
Tartaric Acid ◽  
Disperse System ◽  
Hydrogen Peroxide Solution ◽  
Ultrasonic Pretreatment ◽  
Tartaric Acids ◽  
Inactive Form ◽  
Generating System ◽  
Sole Product

The mechanism of the enzymatic iodination process of diethylmaleate and diethylfumarate (which present no miscibility with water) in the presence of lactoperoxidase, both in diluted hydrogen peroxide solution and in a generating system of hydrogen peroxide using ammonium and calcium iodides as halide sources in disperse system (after an ultrasonic pretreatment) was studied. The obtained sole product (diethyl-2, 3-diiodosuccinate) after the enzymatic iodination process was directly hydrolyzed to a tartaric acid present in an optically inactive form. The mechanism of obtaining the intermediate and final products and respectively, the existence of both D, L-tartaric acid and meso-tartaric acids (as lithium bitartrates) were also investigated.

Rare Earth and Tetra Hydroxymethyl Phosphonium Sulfate Combination Tanning

2012 ◽  
Vol 479-481 ◽  
pp. 430-433
Author(s):  
Ya Li ◽  
Shuang Xi Shao ◽  
Lan Jiang ◽  
Kai Qi Shi
Keyword(s):  
Rare Earth ◽  
Tartaric Acid ◽  
Alkaline Ph ◽  
Uv Spectrum ◽  
Shrinkage Temperature

A new chrome free tanning system of rare earth (RE)-THPS has been developed in this study. It has been proved by UV spectrum that THPS and RE (CeCl3) can coordinate under certain conditions. The influence of CeCl3and THPS’s ratio, pH and ligands on the shrinkage temperature (Ts) was studied. Higher Ts was obtained while the tannage was processed in the sequence of THPS followed by CeCl3. The alkaline pH should be controlled between 5.5 and 6.0 to give ideal tanning effect. It was also found that employing of 0.5% tartaric acid in this combination tanning system can give high Ts of 89°C.

HYDROLYSIS OF CELLULOSE ACETATE SULPHATE IN ACETONE

1954 ◽  
Vol 32 (9) ◽  
pp. 815-822 ◽  
Author(s):  
Karl Keirstead ◽  
John Myers
Keyword(s):  
Acetic Acid ◽  
Cellulose Acetate ◽  
Sulphuric Acid ◽  
Potentiometric Titration ◽  
Titration Method ◽  
Acetate Ester ◽  
Hydrolysis Of Cellulose ◽  
Potentiometric Titration Method ◽  
Hydrolysis Of

When cellulose acetate sulphate is dissolved in acetone the hydrolysis of the sulphate ester is rapid compared with that of the acetate ester. In 70% acetone the relative rates are reversed. Hydrolysis of the sulphate ester in acetone is greatly affected by the temperature. At 25 °C. or greater the hydrolysis is complete after 24 hr. A potentiometric titration method has been developed for the estimation of sulphuric acid in the presence of smaller amounts of acetic acid.

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