• Analytical Science and Technology
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• v.8 no.2
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• pp.139-159
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• 1995

Positive ion mass spectra of some corticosteroids were obtained by using liquid chromatography-mass spectrometry(LC-MS). The base peak of each compound showed the protonated molecular ion [$MH^+$], ammonium adduct ion [${MNH_4}^+$] or [$MH^+-60$] ion according to its chemical structure and other characteristic mass ions were [$MH^+-18$], [${MNH_4}^+-18$] and so on. Several rat urinary metabolites of methylprednisolone acetate after the oral administration were detected by the thermospray LC-MS. The identified major metabolites were 20-hydroxymethylprednisolone(20-HMP), methylprednisolone(MP) and methylprednisone(11-KMP), which were supposed to be formed by deacetylation at the position of C-21, reduction at C-20, oxidation at C-11, or due to the bond cleavage between C-17 and C-20.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.54-59
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• 2003

Several radionuclides are considered as an object of the assesment to develop a scaling factor and a periodical verification method which are needed for the evaluation of radionuclide inventory of various radioactive wastes from nuclear power plants in Korea. A selective separation of $^{55}Fe$, $^{90}FSr$ 및 $^{94}Nb$ which should be recovered individually for the radiochemical analysis was described in detail. Sorption and desorption behaviours of ion exchange and extraction chromatographic resins for Fe, Sr, Nb and co-existing metal ions were Investigated using an artificial waste solution simulated of chemical composition of real radioactive wastes. Separation conditions available for the sequential recovery of these metal ions from a single sample were optimized to minimize a discharge of radioactive wastes produced through the analytical process and a radiation exposure to analysts. Their recovery yields were measured with reliability.

• Korean Journal of Food Science and Technology
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• v.22 no.1
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• pp.56-60
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• 1990

The changes in the partition coefficient of model proteins (lysozyme, myoglobin, conalbumin, bovine serum albumin) in an aqueous two-phase system formed by polyethylene glycol and dextran were examined in order to improve the capacity of counter current distribution for the protein fractionation and concentration. The protein distribution patterns in CCD with 30 tubes varied with the pH of the system, and both theoretical and measured values agreed well. From the mixture of model protein, pure BSA fraction was appeared at the upper-phase of 14th tube having pH 4.5, pure myoglobin at the lower-phase of the 16th be with pH 6.5 and conalbumin at the lower-phase of 4th tube with pH 12. The result indicated the possible use of CCD method for protein fractionation, if the partition coefficient of proteins was manipulated by pH and other means.

• Journal of the East Asian Society of Dietary Life
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• v.9 no.4
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• pp.442-451
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• 1999

This study was conducted to investigate the antimicrobial activity of Prunus mume extracts. Prunus mume extracts have growth inhibitory activity to various microorganisms. Gram positive bacteria such as Bacillus cereus, Bacillus subtilis, Micrococcus leteus, Staphylococcus epidrimidis were more easily inhibited than Gram negative bacteria tested Vibrio parahaemolyticus, Salmonella typhimurium, Escherichia coli, Proteus vulgaris and Yeasts by Prunus mume extracts. Among several fractions of methanol extract, EtOAc & BuOH fractions were showed strong antibacterial activities, but those fractions were not showed on fungi.

• Proceedings of the Culinary Society of Korean Academy Conference
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• 2001.08a
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• pp.29-41
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• 2001

This study was conducted to investigate the antimicrobial activity of Prunus mume extracts. Prunus mume extracts have growth inhibitory activity to various microorganisms. Gram positive bacteria such as Bacillus cereus, Bacillus subtilis, Micrococcus leteus, Staphylococcus epidrimidis were more easily inhibited than Gram negative bacteria tested Vibrio parahaemolyticus, Salmonella typhimurium, Escherichia coli, Proteus vulgaris and Yeasts by Prunus mume extracts. Among several fractions of methanol extract, EtOAc & BuOH fractions were showed strong antibacterial activities, but those fractions were not showed on fungi.

• Analytical Science and Technology
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• v.13 no.1
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• pp.27-33
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• 2000

Simultaneous separation and analysis of Ni(II), Pd(II), Co(II), Cu(II) and Hg(II) in peperidinedithiocarbamate (PDTC) chelates were investigated by reversed phase liquid chromatography. The optimum conditions for the separation of PDTC metal chelates were examined with respect to the pH, extraction solvent, and mobile phase strength on Novapak $C_{18}$ column using methanol/water mixture as mobile phase. All metal PDTC chelates were eluted in an acceptable range of capacity factor value ($0{\leq}log\;k^{\prime}{\leq}1$). The linear calibration curves were obtained in the concentration range of $0{\sim}1.2{\mu}g/mL$ for five metal ions, and also good precision in the range of 1.96~3.41% RSD was obseved. Under the optimum conditions, trace metat ions in the composite water sample were successfully separated and determined with relative error of ${\pm}2.0%$.

• Journal of Korea Water Resources Association
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• v.30 no.5
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• pp.459-465
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• 1997

The possibility of NAPL removal from contaminated soil was studied using the steam injection technique. Both single (octane, toluene and xylene) and composite NAPL (gasoline) were used as contaminant. Soils used in this study were Chumunjin fine sand and weathered granitic soil, both of which are commonly found in Korea. Experimental results showed that with 1 pore volume steam injection, the NAPL removal rate was in the range of 66∼78% for sand and 45∼73% for weathered granitic soil. The steam injection technique seems to have high potential for soil remediation with advantages of relatively short operating time and no side-effect. Rise in the background temperature led to the delay of steam condensation and the increase of NAPL mobility, which resulted in the improvement of removal efficiency. In addition, water flooding after steam injection turned out to be a very efficient way of removing NAPL residual in the soil pores.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1379-1388
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• 2000

Ethanol extracts from Ruta graveolens Linne exhibited strong antimicrobial activities by disc diffusion method against 5 strains of Listeria monocytogenes (ATCC 19111, ATCC 19112, ATCC 19113, ATCC 19114 and ATCC 15313). Ethanol extract from Ruta graveolens Linne was subsequently fractionated by n-hexane, chloroform, ethyl acetate and water. Chloroform fraction of Ruta graveolens Linne showed strong growth inhibition at concentrations as low as 40 ppm level in broth culture medium against 5 strains of L. monocytogenes for 72 hr at $30^{\circ}C$. Single substance(RTG1-1) was isolated by silica gel column chromatography from chloroform fraction of Ruta graveolens Linne. RTG1-1 showed a strong bactericidal activity against L. monocytogenes at a concentration of 20 ppm level. Purified RTG1-1 was identified as gravacridonechlorine by analyses of EI-Mass, $^1H-NMR$ and $^{13}C-NMR$.

• Food Science and Industry
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• v.53 no.3
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• pp.284-294
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• 2020

High voltage pulsed electric field technology has been attracting attention in the the food industry as an eco-friendly nonthermal process technology using electrical energy. The lack of understanding of the equipment and the burden of equipment cost have not significantly increased the commercial application, but the potential as a technology to replace the heat process has been continuously increased. Sterilization of foods using the PEF process has been applied to liquid foods with low viscosity such as fruit and vegetable juices, but recently, high viscosity smoothies, high concentrate protein drink, mixed juice, and alcoholic beverages. Studies on sterilization of solid foods such as powders, raw meats are also being conducted. Also, the application of extraction and recovery of useful ingredients, activation of active compounds, pretreatment of drying, improvement of meat quality, changes of properties of starch has been studies.

• Korean Journal of Metals and Materials
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• v.56 no.12
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• pp.870-877
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• 2018

Cyanex 272 shows the highest separation factor for the rare earth elements from hydrochloric acid solution among the organophosporus acidic extractants, D2EHPA and PC 88A. Solvent extraction of Tb(III) from weak hydrochloric acid solution with an initial pH 3 to 6 was compared with Cyanex 272, its mixture with Alamine 336, and ionic liquid with Aliquat 336. The solvent extraction reaction of Tb(III) using Cyanex 272 was the same as that of light rare earth elements. Synergism was observed for the extraction of Tb(III) by the mixture with Alamine 336 when the initial concentration ratio of Cyanex 272 to Alamine 336 was higher than 5. Use of the ionic liquid led to a great increase in the extraction percentage of Tb(III) from the same initial extraction conditions. While the equilibrium pH of the mixture was always lower than the initial pH, under some conditions extraction with the ionic liquid resulted in a higher equilibrium pH than the initial pH. The loading capacity of the mixture and the ionic liquid was the same and 2.6 times larger than that using Cyanex 272 alone. Ionic liquid was recommended as a suitable extractant for the extraction of Tb(III) from hydrochloric acid solution based on the ease of handling and higher extraction percentage.