preliminary purification
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Author(s):  
A. S. Alekseeva ◽  
T. B. Shemeryankina ◽  
M. N. Lyakina ◽  
M. S. Smirnova ◽  
E. P. Fedorova ◽  
...  

Vitamin A is present in multivitamin products mainly in the form of retinol esters: retinyl acetate, retinyl palmitate, and beta carotene—retinol precursor (dimer) found in plants, which is capable of converting into retinol in liver cells. Retinol is determined in medicinal products primarily by high performance liquid chromatography (HPLC), with preliminary purification and vitamin isolation by liquid-liquid extraction. However, scientific literature also describes other methods of sample preparation and analysis of such compounds. An important issue is differentiation of vitamin A from other fat-soluble vitamins often included as components in multivitamin products. The aim of the study was to analyse and summarise data on current methods used for determination of vitamin A and its derivatives in medicinal products. The authors analysed the range of vitamin A products authorised in the Russian Federation, and the test methods described in their product specification files. The study demonstrated that the test method most often used for determination of retinol esters was HPLC with isocratic elution mode using octadecylsilyl packing in the reverse-phase mode, and, less frequently, aminopropylsilyl packing in the normal phase mode. Determination of beta carotene in medicinal products is most often performed using spectrophotometry. 


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1599
Author(s):  
Hsin-Yi Hung ◽  
Shih-Min Lin ◽  
Chia-Ying Li ◽  
Sio-Hong Lam ◽  
Yu-Yi Chan ◽  
...  

A highly specific and sensitive proton nuclear magnetic resonance (1H-NMR) method has been developed for the quantification of ephedrine alkaloid derivatives in Ephedra herbal commercial prescriptions. At the region of δ 4.0 to 5.0 ppm in the 1H NMR spectrum, the characteristic signals are separated well from each other, and six analogues in total, methylephedrine (ME), ephedrine (EP), norephedrine (NE), norpseudoephedrine (NP), pseudoephedrine (PE), and methylpseudoephedrine (MP) could be identified. The quantities of these compounds are calculated by the relative ratio of the integral values of the target peak for each compound to the known concentrations of the internal standard anthracene. The present method allows for a rapid and simple quantification of ephedrine alkaloid derivatives in Ephedra-related commercial prescriptions without any preliminary purification steps and standard compounds, and accordingly it can be a powerful tool to verify different Ephedra species. In comparison to conventional chromatographic methods, the advantages of this method include the fact that no standard compounds are required, the quantification can be directly performed on the crude extracts, a better selectivity for various ephedrine alkaloid derivatives, and the fact that a very significant time-gain may be achieved.


Author(s):  
V. N. Shkura ◽  
◽  
A. S. Shtanko ◽  

Purpose: development of justification for the feasibility and possibility of application and structure schemes of filtering water intakes for water intake from canals, its preliminary purification and supply to drip irrigation systems. Materials and Methods. During development of justification, general and specific scientific methods of analysis and synthesis of information on the advantages and disadvantages of filtering water intakes were used, and during the development of their designs, technologies of research design were used. Results and Discussion. It has been found that filtering water intakes can simultaneously perform the functions of water intake, trash barriers, fish protection and purification facilities. Structural flexibility and simplicity of performance, environmental friendliness, multifunctionality and high technical and economic indicators are the basic characteristics that made it possible to substantiate the feasibility of their application as water intake and treatment facilities for drip irrigation systems. As a result of the research, at the level of inventions, structural schemes of water intake structures with inlets equipped with filter panels with bottom and slope locations were developed. The water intakes provide for the arrangement of catchment and water storage containers, ensuring the water collection seeped through the filter panels and its subsequent drainage into the water conducting stream. The water intake structures provide for the possibility of selective water intake from the least polluted horizons of the water flow. The problematic issues of the use of filtering water intakes are noted in terms of the need to create a developed water intake front and periodic flushing or replacement of filtering panels. Conclusions. The feasibility of using water intake purification facilities, providing water intake from water sources and its preliminary treatment for the needs of drip irrigation systems, has been substantiated, as well as filtering water intakes designs recommended for the arrangement and use in drip irrigation systems are proposed.


Author(s):  
C. I. Nnamchi ◽  
B. C. Nwanguma ◽  
O. C. Amadi

Catalases are key components of cellular detoxification pathways that prevent the formation of highly reactive hydroxyl radicals through catalyzing the decomposition of hydrogen peroxide into water and molecular oxygen. Their presence in brewery grains prevent the inactivation of important brewery enzymes and also stop lipid peroxidation. To determine their occurrence and establish some of its properties in sorghum, which has become as an important brewery grain similar to barley, crude catalase was obtained from a sorghum grain variety. Preliminary purification of catalase from the sorghum grain variety used, NRL-3, showed that the enzyme was purified 3.2-fold from the crude protein to give a 49% yield of the partially purified enzyme, with a final specific activity of 32 Umg-1 proteins. There was also a positive indication of sorghum catalase presence on SDS PAGE with positive bands occurring between the range of 48-62 kDa. Therefore, the molecular weight of sorghum catalase most likely falls within the two bands. The enzyme showed a narrow pH range with optimum activity occurring at pH 7. Similarly, its optimum activity temperature occurred at 40°C.  This work is the first reported attempt at purifying catalase from sorghum.


2020 ◽  
Vol 164 ◽  
pp. 01020
Author(s):  
Nikolay S. Serpokrylov ◽  
Alla S. Smolyanichenko ◽  
Elena V. Yakovleva

This article proposes a solution to the urgent problem of treating oil-, fat-containing wastewater. A phase separator of dispersions for preliminary purification of industrial wastewater contaminated with fats is proposed, its effectiveness in the treatment of wastewater at local treatment facilities of an industrial plant for the production of sunflower oil is tested. In order to reduce the cost of acquiring reagents and increase the efficiency of purification of fat-containing wastewater, the use of carbide sludge and sodium hydroaluminate was studied. Laboratory studies conducted by the method of an active experiment.


Author(s):  
Efroim P. Lokshin ◽  
Olga A. Tareeva ◽  
Tatyana A. Sedneva ◽  
Irina R. Elizarova

The aim of the work is the continuation of the development of a new efficient hydrochemical technology for the processing of apatite concentrate, which makes it possible to produce phosphoric acid with a reduced content of impurities as a product, to use all the valuable components of apatite concentrate. The dependence of the efficiency of decomposition of apatite concentrate with a phosphate acid solution at a temperature of 20 and 50 °C in the presence of sulfate cationite КУ-2-8чС in Na+- and K+ - forms was studied. The influence of the decomposition conditions (expense and form of sorbent, the ratio of liquid: solid, the interaction temperature) on the degree of decomposition of the concentrate, the completeness of absorption by the sorbent of the metallic cations of the concentrate, the content of impurities in the resulting phosphate-acid solution, and the composition of undissolved residues are studied. The possibility of achieving a high degree of decomposition of the concentrate (up to 99.5 %) is established. High sorption efficiency of calcium and strontium (up to 90.2 and 93.4 % respectively) is shown. The sorption of REE of the cerium group was better than the REE of the middle and yttrium groups. Increasing the temperature from 20 to 50 °C reduced REE sorption by 14-170%. Aluminum, thorium and uranium were the most difficult to sorb. It has been found that effective purification of phosphoric acid from the impurity of fluorine is achieved directly in the process of decomposition. The efficiency of purification from fluorine when using a sorbent in the K+ - form is greater than when using a sorbent in the Na+- form. It is shown that the obtained acid can be purified from sodium or potassium by the electrodialysis method in a two-chamber electrodialyzer equipped with a cation exchange membrane. It is found that before electrodialysis, preliminary purification of the phosphate solution from calcium, which is obtained during the decomposition of apatite concentrate, is necessary. To this purpose, an additional purification of the phosphoric acid solution by sulphocathionite sorption has been investigated. The lower sorption from the phosphoric acid solution of Al, Ti, Fe, Th, and U is explained by the formation of stable anionic complexes or undissociated molecules by these elements. The developed technology for the production of phosphoric acid from the apatite concentrate does not require the use of sulfuric acid, has a number of other advantages. The content of impurities in the resulting phosphoric acid is much less than in the extraction phosphoric acid produced by the sulfuric acid processing of apatite concentrate.


2018 ◽  
pp. 455-462
Author(s):  
Q.Y. Cui ◽  
X.H. Ni ◽  
L. Zeng ◽  
Z. Tu ◽  
J. Li ◽  
...  

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