• Journal of the Korean Crystal Growth and Crystal Technology
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• v.6 no.4
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• pp.584-594
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• 1996

For the separation and purification of aluminium chloride hexahydrate crystals from kaolin leaching solution the effects of crystallization conditions, such as crystallization temperature, concentration of aluminium chloride concentration in the leaching solutin and gas flow rate of HCl into the leaching solution, on purity of the aluminium chloride hexahydrate crystals were investigated. The supersaturation level of aluminium chloride in the leaching solution gave great influence on the purity of the crystals. When supersaturated concentration of the aluminium chloride in the leaching solution was generated in low level, the aluminium chloride hexahydrate crystals were produced with high purity ; that is, the crystals hving a low Fe-ion concentration. The supersaturation level of aluminium chloride in the leaching solution was mainly determined by crystallization temperature, concentrations of aluminium chloride and hydrochloric acid in the solution. However, in spite of changes of the above crystallization coditions, a needle shape morphology of aluminium chloride hexahydrate crystals did not modified. To measure hydrochloric acid concentration in the kaolin leaching solution, we applied the oxalate titration method, which was suggested by shank [9] and it was prove that this method could titrate hydrochloroic acid concentration in multi-component ionic solution such as kaolin leaching solution.

• Fisheries and Aquatic Sciences
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• v.15 no.3
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• pp.191-195
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• 2012

We report here the use of high-speed countercurrent chromatography (HSCCC) in the preparative isolation and purification of the bioactive component, fucosterol, from Pelvetia siliquosa. A crude extract was obtained by ultrasonic extraction of powdered P. siliquosa using methylene chloride and was then subjected to separation and purification by HSCCC, coupled with evaporative light-scattering detection. Preparative HSCCC was performed successfully using a two-phase solvent system, n-heptane:methanol (3:2, v/v), to obtain 10.96 mg fucosterol with 96.8% purity from 50 mg of crude extract; the recovery rate was approximately 90.5%.

• Journal of Microbiology and Biotechnology
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• v.28 no.10
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• pp.1749-1759
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• 2018

Recombinant (rec) prion protein (PrP) is an extremely useful resource for studying protein misfolding and subsequent protein aggregation events. Here, we report mass production of high-purity rec-polypeptide encoding the C-terminal globular domain of PrP; (90-230) for human and (89-231) for murine PrP. These proteins were expressed as His-tagged fusion proteins in E. coli cultured by a high cell-density aerobic fermentation method. RecPrPs recovered from inclusion bodies were slowly refolded under reducing conditions. Purification was performed by a sequence of metal-affinity, cation-exchange, and reverse-phase chromatography. The current procedure yielded several dozens of milligrams of recPrP per liter with >95% purity. The purified recPrPs predominantly adopted an ${\alpha}$-helix-rich conformation and were functionally sufficient as substrates to measure the seeding activity of human and animal prions. Establishment of a procedure for high-level production of high-purity recPrP supports the advancement of in vitro investigations of PrP including diagnosis for prion diseases.

• Applied Chemistry for Engineering
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• v.33 no.2
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• pp.166-172
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• 2022

A method of efficiently purifying high value-added indole among components of coal tar absorption oil was studied using a step-by-step process of extraction-distillation-crystallization. The coal tar absorption oil used in this study contains 1.2% naphthalene, 0.1% quinoline, 0.4% isoquinoline, 6.4% indole, 21.0% 1-methylnaphthalene, 48.8% 2-methylnaphthalene, and 11.7% biphenyl as main components. For the separation and purification of indole, methanol was first used as a solvent to separate indole species in the coal tar absorption oil into an extract phase. And then methanol was recovered by distillation. Subsequently, an extraction solution where methanol was removed was mixed with normal hexane, and then crystallized to recover indole having a purity of 99.3%. Based on the experiments of this study, a purification process scheme for indole in coal tar absorption oil was proposed.

• Bulletin of the Korean Chemical Society
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• v.29 no.2
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• pp.389-392
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• 2008

High purity carbon nano fibers/tubes (CNF/Ts) which contain 97% pure graphitic carbon are prepared by a new catalytic method. These carbon nano fibers/tubes are ready to use without any further purification. The striking feature of this method is the production of carbon nano fibers/tubes of narrow distribution range. The developed catalytic method also produces pure hydrogen. An additional advantage of this catalytic method is that catalyst can be reused without reactivation. Ni:Cu catalyst system is embodied into SCHOTT-DURAN filter disc of large pore size (40-100 mm). Due to the production of hydrogen in the reaction catalyst stability is enhanced and deactivation process is considerably slowed down.

• Journal of Korea Foundry Society
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• v.13 no.6
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• pp.540-546
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• 1993

The effects of fluid flow on the purification of aluminum were studied. As the revolution rate(N) increased, the size of columnar grain decreased gradually. The concentration of solidified crystal was decreased with increasing distance from chill and revolution rate(N). Distribution boundary layer thickness(${\delta}$) was calculated from the solute distribution obtained in solid experimentally and by use of BPS equation. The value of ${\delta}$ changed from about $60{\mu}m$ at N value of 27rpm to about $15{\mu}m$ at N value of 1000rpm. From this result, high purification was obtained by decreasing the diffusion boundary layer under forced convection.

• The Plant Pathology Journal
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• v.15 no.1
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• pp.34-37
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• 1999

Cymbidium mosaic virus (CyMV) was purified from CyMV infected orchid plant leaves by Sephacryl S-500 HR column chromatography. Partial purification was done by solubilization with Triton X-100 (alkylphenoxypolyethoxy ethanol) and precipitation with polyethylene glycol (PEG 6,000) followed by ultracentrifugation on 30% sucrose cushion. Based on the spectrophotometric analysis, 33 mg of CyMV could be obtained form 100 g of CyMV-infected orchid plant leaves. The purified CyMV represented one distinct homogeneous band by SDS-PAGE, and electron microscopy revealed that it was highly homogeneous and not fragmented. Bioassay demonstrated that the purified CyMV had a normal infectivity to Chenopodium amaranticolor and orchid plants. Based on these results, the purification method in this work could be served as an improved method for the purification of CyMV and similar viruses with good yield, high purity and native integrity.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2647-2650
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• 2009

Cold shock proteins (Csps) are a subgroup of the cold-induced proteins on reduction of the growth temperature below the physiological temperature. They preferentially bind to single-stranded nucleic acids to translational regulation via RNA chaperoning. Csp plays important role in cold adaptations for the psychrophilic microorganism. Recently, Cold shock protein from psychrophilic bacteria, Colwellia psychrerythraea (CpCsp) has been identified. Three dimensional structures of a number of Csps from various microorganisms have been solved by NMR spectroscopy or X-ray crystallography, but structures of psychrophilic Csps were not studied yet. Therefore, cloning and purification protocols for further structural study of psychrophilic Csp have been optimized in this study. CpCsp was expressed in E. coli with pET-11a vector system and purified by ion exchange, size exclusion, and reverse phase chromatography. Expression and purification of CpCsp in M9 minimal media was carried out and $^{15}N$-labeled proteins with high purity over 90% was obtained. Further study will be carried out to investigate the tertiary structure and dynamics of CpCsp.

• Resources Recycling
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• v.31 no.2
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• pp.20-32
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• 2022

This study implemented a chelating agent (Ethylenediaminetetraacetic acid, EDTA) in purification to obtain high-purity vanadium pentoxide (V₂O₅) for use in VRFB (Vanadium Redox Flow Battery). V₂O₅ (powder) was produced through the precipitation recovery of ammonium metavanadate (NH₄VO₃) from a vanadium solution, which was prepared using a low-purity vanadium raw material. The initial purity of the powder was estimated to be 99.7%. However, the use of a chelating agent improved its purity up to 99.9% or higher. It was conjectured that the added chelating agent reacted with the impurity ions to form a complex, stabilizing them. This improved the selectivity for vanadium in the recovery process. However, the prepared V₂O₅ powder exhibited higher contents of K, Mn, Fe, Na, and Al than those in the standard counterparts, thus necessitating additional research on its impurity separation. Furthermore, the vanadium electrolyte was prepared using the high-purity V₂O₅ powder in a newly developed direct electrolytic process. Its analytical properties were compared with those of commercial electrolytes. Owing to the high concentration of the K, Ca, Na, Al, Mg, and Si impurities in the produced vanadium electrolyte, the purity was analyzed to be 99.97%, lower than those (99.98%) of its commercial counterparts. Thus, further research on optimizing the high-purity V₂O₅ powder and electrolyte manufacturing processes may yield a process capable of commercialization.

• BMB Reports
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• v.31 no.4
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• pp.377-383
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• 1998

Thioltransferase, also known as glutaredoxin, was purified from Chinese cabbage (Brassica campestris ssp. napus var. pekinensis) by a combination of ion-exchange chromatography and gel filtration. Its purity was confirmed by SDS-polyacrylamide gel electrophoresis and its molecular weight was estimated to be about 12,000 which is comparable with those of most known thioltransferases. The enzyme utilizes 2-hydroxyethyl disulfide, S-sulfocysteine, ${\alpha}-chymotrypsin$, insulin, and trypsin as substrates in the presence of reduced glutathione. The enzyme has Km values of 0.03-0.97 mM for these substrates. It appeared to contain dehydroascorbate reductase activity. The pH optimum of the enzyme was 8.5, when 2-hydroxyethyl disulfide was used as a substrate. It was greatly activated by reduced glutathione. Its activity was not significantly lost when stored at high temperature, indicating its thermostable character. It may play an important role in thiol-disulfide exchange in plant cells.