• Analytical Science and Technology
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• v.16 no.2
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• pp.110-116
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• 2003

A study has been done on the separation of iodide from spent pressurized water reactor (PWR) fuels and its quantitative determination using ion chromatography. Spent PWR fuels were dissolved with mixed acid of nitric and hydrochloric acids (80 : 20 molL%) which can oxidize iodide to iodate to prevent it from be vaporized. After reducing ${IO_3}^-$ ­to $I_2$ in 2.5 M $HNO_3$ with $NH_2OH{\cdot}HCl$, Iodine was selectively separated from actinides and all other fission products with carbontetrachloride and back-extracted with 0.1 M $NaHSO_3$. Recovered iodide was determined using the ion chromatograph of which the column was installed in a glove box for the analysis of radioactive materials. In practice, spent PWR fuel with 42,000~44,000 MWd/MtU was analyzed and its quantity was compared to that calculated by burnup code, ORIGEN2. The agreement was achieved with a deviation of -8.3~-0.5% from the ORIGEN 2 data, $324.5{\sim}343.6{\mu}g/g$.

• Journal of the Korean Applied Science and Technology
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• v.6 no.1
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• pp.27-30
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• 1989

The fast separation and determination of cefatrizine${\cdot}$propylene glycol and inmpurities - TACA: 7-amino-3-(1,2,3-triazol-4-yl)thiomethyl-3-cephem-4-carboxylic acid and 7-ACA; 7-amino cephalosporanic acid - was performed by the high poerformance liquid chromatography using octadecyl siland (ODS) column. Methanol and ammonium phosphate buffer [$0.03M(NH_4)_2\;HPO_4$, (pH 7.5)] was used analyze, as eluent. The experimental value of the contents of cefatrizine${\cdot}$propylene glycol and impurities agree with the theoretical value of those.

• Korean Journal of Microbiology
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• v.23 no.4
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• pp.241-247
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• 1985

The objectives of this study were to isolate and identify ninhydrin positive substande(s) produced in the culture broth of Pseudomonas fluorescens. It was found that the NPS could stimulate bioconversion of furfural into furoic acid. In order to isolate the NPS from the culture broth, cell free filtrate was subjected to ion-exchange chromatography, gel-permeation and finally to cellulose column chromatography. The purified NPS was white amorphous power and very soluble in water, slightly soluble in methanol and very insoluble in organic solvents. UV, and IR absorption spectra. $^H$ and $^{13}C-NMR$ were measured in order to identify the chemical structure of the NPS.

• Applied Biological Chemistry
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• v.48 no.4
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• pp.364-369
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• 2005

This study was performed to elucidate substrate specificity to the locust bean gum galactomannan by Trichoderma harzianum ${\beta}-mannanase$. The medium composition for enzyme production were determined 3% cellulose, 3% corn steep liquor, 1% $KH_2PO_4$, 0.2% $(NH_4){_2}SO_4$, and incubated for 115 hr at $28^{\circ}C$. The ${\beta}-mannanase$ exhibited maximum activity at pH 4.5 and $60^{\circ}C$. Locust bean gum galactomannan was hydrolyzed by the ${\beta}-mannanase$, and then hydrolysates separated by activated carbon column chromatography. The main hydrolysates were composed of D.P 4 and 7 galactosyl mannooligosaccharides by TLC. For the elucidate the structure of D.P 4 and 7 oligosaccharides, methylation analysis was performed. D.P 4 and 7 were identified as M-M-M-M and M-M-M-M-M (G- and M-represent ${\alpha-1,6-D-galactosidic\;and\;{\beta}-1,4-mannosidic$ linkages, respectively). //G-G To investigate the effects of locust bean gum galactosyl mannooligosaccharides on the in vitro growth of B. longum, B. bifidum, B. infantis, and B. breve, Bifidobacterium spp. were cultivated individually on the modified-MRS medium containing carbon source such as D.P 4 and 7 galactosyl mannooligosaccharides, respectively. B. longum grew up 3.4-fold and 4.3-fold more effectively by the replacement of D.P 4 and 7 galactosyl mannooligosaccharides as the carbon source in a comparasion of standard MRS.

• Korean Journal of Veterinary Service
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• v.36 no.4
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• pp.303-309
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• 2013

This study was conducted to determine the content of 7 mycotoxins (aflatoxin $B_1$, $B_2$, $G_1$, $G_2$, $M_1$, ochratoxin A and zearalenone) using LC-MS/MS in pork available on the Korean markets. The analysis was carried out using following conditions; C18 column ($2.1{\times}100mm$, $1.7{\mu}m$), mobile phase composed of $H_2O$ (0.1 mM $NH_4Ac$ 0.01% HCOOH) : Methanol (0.1 mM $NH_4Ac$ 0.01% HCOOH), binary pump at a flow rate of 0.5 mL/min and $2{\mu}L$ of injection volume, MS/MS detector with ESI positive and negative mode. The quantication of mycotoxins was based on matrix-matched calibration curves with a correlation coefficient in excess of 0.99 for the 7 mycotoxins. The dectection limits were ranged 0.74~2.13 ng/g, with mean recoveries between 73.10~97.46% except aflatoxin $B_1$ (61.31%). We also monitored mycotoxin residues in 208 pork samples. The test results, mycotoxins were not found except one sample. Ochratoxin A in one sample of the test samples was detected below the quantification limit.

• Journal of the Korean Chemical Society
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• v.29 no.2
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• pp.178-182
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• 1985

The purpose of this study was to develop a separation method of Zn(II), Cu(II) and Mg(II), by ion exchange chromatography using cation exchange resion (Dowex 50w${\times}$8, 80-100 mesh) and anion exchange (Amberlite IRA-400). Ion exchange resions were packed into 25 ${\times}$ 2cm ID column and flow rate was controlled to 0.30 ml/min. Good eluents for separation of nonferrous metal ions such as Zn(II), Cu(II), Mg(II) were as follow: 0.5M $NaNO_3$ (pH 3.1), 0.2~0.5M HCl + 50~60% Acetone, and 1M HAc + 0.1M NaAcf(pH 3.7) aqueous solution. The mixed solution of 0.1M NaAc(pH 3.7), 0.5M HCl + 50% Acetone were found to be the best eluent for step elution. Analysis of metals were determined by atomic absorption spectrophotometer. In addition, separated Zn(II) fraction was obtained by eluted with 0.12N HCl and 1.5N $NH_4OH$ aqueous solution. This solution was titrated by the E. D. T. A.

• KSBB Journal
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• v.23 no.2
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• pp.135-141
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• 2008

SMB (simulated moving bed) chromatography is a very useful utility for the separation of binary system. We simulated the separation of L-arabinose and L-ribose from the mixture by using lab-scale 4(1-1-1-1)-zone SMB chromatography. Preliminary experiments of PIM (pulse input method) were performed to measure adsorption isotherms of L-ribose and L-arabinose in $NH_2$ HPLC column, and experimental and simulated results from ASPEN chromatography were compared. To find the most suitable separation condition in SMB, we carried out a simulation in $m_2-m_3$ plane base on the triangle theory and calculated operating parameters (flow rate of four zone, switching time and feed concentration and so on) using ASPEN chromatography under the conditions of linear isotherms obtained from PIM.

• Microbiology and Biotechnology Letters
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• v.17 no.4
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• pp.370-378
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• 1989

An Alkalophilic Bacillus circulans that can produce significant amount of cyclodextrin glucanotransferase (CGTase) was newly isolated from soil. The culture filtrate was successively purified by ($NH_4$)$_2$$SO_4$precipitation, DEAE-Sephadex column chromatography, and Sephadex G-100 column chromatography. The enzymatic properties, including molecular weight, optimal pH and temperature, stability, and kinetic parameters, were determined. The cyclodextrin synthesis reaction catalized by the purified CGTase was also studied. The sweet potato and corn starch were found to be the most suitable substrates with 60% conversion to cyclodextrin. The highest conversion was achieved at the CGTase concentration of 900-1,100 units/g of soluble starch. The purified CGTase could also catalize the transglycosylation on stevioside.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.2
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• pp.201-208
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• 2010

The $SO_2$ and $NO_x$ removal with an activated coke catalyst was conducted by a two-stage reaction which first $SO_2$ was oxidized to $H_2SO_4$ and then $NO_x$ was reduced to $N_2$. But if unreacted sulfur dioxide entered in the second stage, the $NO_x$ reduction was hindered by the reaction with ammonia. In this study, experimental investigations by using lab-scale column apparatus on the product and the reactivity of $SO_2$ with ammonia over coke catalyst which was activated with sulfuric acid was carried out through ultimate analysis DTA, TGA and SEM of catalyst before and after the reaction. Also, the effect of reaction emperature on the reactivity of $SO_2$ with ammonia was determined by means of breakthrough curves with time. The obtained results from this study were summarized as following; Activated cokes were decreased carbon component and increased oxygen and sulfur components in comparison with original cokes. The products over coke catalyst were faced fine crystal of $(NH_4)_2SO_4$, which results in the pressure loss of reacting system. The order of general reactivity in terms of the reaction temperature after breakthrough for $SO_2$ was found to be $150^{\circ}C$ > $200^{\circ}C$ > $100^{\circ}C$. This was related to adsorption amounts of ammonia on the activated cokes.

• Journal of the Korean Chemical Society
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• v.41 no.11
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• pp.612-638
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• 1997

The methods of separation and recovery of rare earth elements in monazite sand have been studied by the ion exchange chromatography. Both of cation and anion exchange resin were used as ion exchange resins and the solutions of EDTA, DTPA, IMDA and Ln-EDTA were used as eluents. The H+, Zn2+, Fe3+, Al3+, Cu2+, and NH4+ forms of cation exchange resin were used as retaining ions. Ln-EDTA solution was loaded on the EDTA form of anion exchange resin and separated. The Ln-EDTA solution was also used as an eluent for a selective separation of one element from the rare earth mixture solution. The size effects of resin column, the elution mechanism for the various elution types and the separation of a large amount of rare earths were studied.