• KSBB Journal
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• v.15 no.1
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• pp.60-65
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• 2000

In order to predict the chromatogram for organic acid in ion chromatography, Langmuir isotherm parameters were obtained by Retention Time Method (RTM) and moment method. Ion chromatography analysis for formic acid was performed and compared with theoretically predicted profiles under isocratic condition. Band profiles were estimated with the equilibrium-dispersive model of chromatography using a PDEsolver Macsyma . The relationship between the characteristics of chromatogram and the variable operating condition in chromatography such as the flow rate, ionic strength and injection volume was studied. Satisfactory agreement was observed between the experimental and the estimated chromatograms with parameters obtained form the moment method.

• Journal of Soil and Groundwater Environment
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• v.16 no.6
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• pp.122-132
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• 2011

Mercury accumulates in biota mainly as methylmercury. In nature, methylmercury shows high affinity to organic matter and $CH_3Hg^+$-organic matter complexation affects the mobility and bioavailabiity of methylmercury. In this study, we examined the methylmercury binding sites in an aquatic humic acid as affected by the pH condition using Hg $L_{III}$-edge extended X-ray absorption fine structure (EXAFS). We evaluated methylmercury binding humic ligands using methylmercury-thiol, methylmerury-carboxyl, and methylmercury-amine complexation models. When $CH_3Hg^+$-to-humic reduced sulfur ratio is 0.3, we found that most of $CH_3Hg^+$ binds to thiol ligands at pH 5 and 7. At pH 7, however, some carboxyl or amine ligand contribution is observed, unlike at pH 5 where $CH_3Hg^+$ almost exclusively binds to thiol ligands. The carboxyl or amine ligand contribution may indicate that some types of thiol ligands in the natural organic matter have relatively low complexation constants or acid dissociation constants compared to those of some carboxyl or amine ligands. Analysis results indicate that ~0.2 fraction of methylmercury binds to amine or carboxyl ligands and ~0.8 to thiol ligands at pH 7.

• Journal of the Korean Chemical Society
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• v.36 no.1
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• pp.125-130
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• 1992

Stereoisomers of trifluoroethylmandelate(mandelic acid trifluoroethylester) were synthesized from each isomer of mandelic acid and trifluoroethanol with p-toluene sulfonic acid in order to study the enantioselectivity of lipase in organic solvent. The products were identified by $^1H$ NMR and elemental analysis and their physical properties such as melting point, densities and specific optical rotations($[{\alpha}]_{25}{^D}$) were also characterized. $[{\alpha}]_{25}{^D}$ of (+)- and (-)-trifluoroethylmandelate were +74° and -75.4°, respectively. The trifluoroethylmandelate was found out to be as a good substrate for the transesterfication stereoselectivity of lipases in organic solvent. Any significant difference of the lipase catalyzed transesterification activity between (+)- and (-)-methylchloropropionate was not found, and even lipase activity of transesterfication was not found with high optical polar (+)-and (-)-methylmandelate.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.12 no.1
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• pp.23-34
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• 2012

Purpose: Acute symptomatic seizures are caused by structural changes, inflammation or metabolic changes of brain, such as tumor, stroke, meningitis, encephalitis and metabolic disorders. Inherited metabolic disorders that can cause seizures are organic acidopathies, lysosomal storage disorders, peroxisomal disorders and mineral disorders. We have done this study to find out the importance of organic acidopathies causing seizure disorders in Korean childhood and adolescent patients. Method: Retrograde analysis for 1,306 patients with seizure disorders whose clinical informations are available and have done urine organic acid analysis for 5 years period, between Jan. 1st 2007 to Dec. 31th 2011. Statistical analysis was done with Student's t test using SPSS. Result: Out of 1,306 patients, 665 patients (51%) showed abnormalities on urine organic acid analysis. The most frequent disease was mitochondrial respiratory chain disorders (394, 30.1%), followed by mandelic aciduria (127, 9.7%), ketolytic defects (81, 6.2%), 3-hydroxyisobutyric aciduria (19, 1.4%), glutaric aciduria type II (10, 0.8%), ethylmalonic aciduria (4), propionic aciduria (4), methylmalonic aciduria (3), glutaric aciduria type I (3), pyruvate dehydrogenase deficiency (3), pyruvate carboxylase deficiency (3), isovaleric aciduria (2), HMG-CoA lyase deficiency (2), 3-methylcrotonylglycinuria (2), fatty acid oxidation disorders (2), fumaric aciduria (1), citrullinemia (1), CPS deficiency (1), MCAD deficiency (1). Conclusion: On neonatal period, mandelic aciduria due to infection was found relatively frequently. Mitochondrial disorders are most frequent etiologic disease on all age group, followed by ketolytic defects and various organic acidopathies. The number and diversities of organic acidopathies emphasize meticulous evaluation of basic routine laboratory examinations and organic acid analysis with initial sample on every seizure patient.

• Korean Journal of Pharmacognosy
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• v.41 no.1
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• pp.62-66
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• 2010

In result of analysis for the content determination of ursolic acid(UA) and oleanolic acid(OA) in extract of Eriobotryae folium using HPLC with UV detector, UA in chloroform extract of Moo-mok variety was showed highest content(2.7843 mg/g). And OA in ethyl acetate extract of Dae-bang variety was showed highest content(0.5898 mg/g). These result suggest that direct extraction using organic solvent(chloroform or ethyl acetate) was useful method for rapid quantitative analysis of UA and OA without preprocessing such as drying or fractionation.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.3
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• pp.41-51
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• 2012

Biohydrogen production and analysis of microbial community were attempted from the sugar manufacturing wastewater with anaerobic fermentation process. Addtion of nutrients ($N{\cdot}P$) into sugar manufacturing wastewater stimulates hydrogen production from 9.53 to $26.67m{\ell}$ $H_2/g$ COD. Butyric acid, acetic acid, lactic acid, and propionic acid were detected in the sample of the anaerobic fermentation process. Butyric acid/Acetic acid(B/A) ratio was increased 0.50 to 0.92 according to the nutrients addtion into the wastewater. Microbial community was analyzed as Clostridium sp. in the phylum of Firmicutes and Klebsiella sp., Erwinia sp., and enterobacter sp. of the class of $\gamma$-Proteobacteria. As the improvement of hydrogen production, Erwinia sp. was decreased and Klebsiella sp. was increased.

• Clinical and Experimental Pediatrics
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• v.49 no.3
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• pp.329-331
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• 2006

Alkaptonuria is a rare metabolic disease in which homogentisic acid cannot be metabolized due to a lack of the enzyme homogentisic acid oxidase. The disease often manifests itself in childhood by darkening of the urine upon standing. The disease leads to such serious consequences as ochronosis of cartilage and connective tissues with arthritis. It is expected that treatment with ascorbic acid and a dietary restriction of protein may decrease the late and serious consequences by diminishing the serum concentration of the metabolite benzoquinone acetic acid. A thirteen month-old girl was recently diagnosed with alkaptonuria by urine organic acid analysis. She excreted pinkish urine on a diaper and as time went by the urine color changed to a light brown. In laboratory findings, urine examination and culture results were normal. But urine organic acid analysis detected abnormal findings a prominent and massive elevation of homogentisic acid. The other physical findings were normal. This is the first case diagnosed in Korea.

• Journal of Microbiology and Biotechnology
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• v.27 no.11
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• pp.2019-2027
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• 2017

Recently, cabbage kimchi has occasionally been associated with the foodborne diseases of enteric viruses such as human norovirus (HuNoV). This study aimed to evaluate the correlation between microbial/physicochemical properties and persistence of HuNoV in experimentally contaminated cabbage kimchi fermented and stored at $4^{\circ}C$ or $10^{\circ}C$ for 28 days. Changes in organic acid content, lactic acid bacteria (LAB), acidity, pH, and salinity were analyzed. The recovery of structurally intact HuNoV was examined for up to 28 days post-inoculation, using a NoV GII.4 monoclonal antibody-conjugated immuno-magnetic separation method combined with quantitative real-time reverse transcription polymerase chain reaction. On day 0, LAB loads were $4.70log_{10}$ colony forming units/g and HuNoV GII.4 titers were $2.57log_{10}\;genomic\;copies/{\mu}l$, at both temperatures. After 28 days, intact HuNoV titers decreased to 1.58 ($4^{\circ}C$) and $1.04(10^{\circ}C)log_{10}\;genomic\;copies/{\mu}l$, whereas the LAB density increased. This correlated with a gradual increase in lactic acid and acetic acid at both temperatures. Our findings support a statistical correlation between changes in physicochemical properties and the recovery of structurally intact HuNoV GII.4. Moreover, we determined that the production of organic acid and low pH could affect HuNoV GII.4 titers in cabbage kimchi during fermentation. However, HuNoV GII.4 was not completely eliminated by microbial/physicochemical factors during fermentation, although HuNoV GII.4 was reduced. Based on this, we speculate that the persistence of HuNoV GII.4 may be affected by the continually changing conditions during kimchi fermentation.

• Korean Journal of Clinical Laboratory Science
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• v.40 no.2
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• pp.147-152
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• 2008

Due to the development and expansion of industries and medical standards, the number of workers who handle organic solvents within hospitals is increasing. The authors in this study intended to investigate the actual conditions of the handling of the solvents and to encourage the recognition that the exposure to such solvents may be possible because of insensitivity to safety. In order to investigate the actual conditions of exposure of workers within hospitals, the experimental group included the three sections (Pathology department, Central Supply Room, and Operating Room), which handle organic solvents most frequently. Meanwhile, university interns were selected to be the control group. This study was conducted between May 1 to May 30, 2007, and urine was taken as samples. Hippuric acid, mandelic acid, methylhippuric acid, and phenylglyoxylic acid were analyzed through gas chromatography, and a total of 52 subjects of the experimental and the control groups were performed of the analysis. As for the results of the analysis of the experimental group, the exposure to benzene was $42.27{\pm}3.70mg/g$ creatinine, that of xylene was $1.30{\pm}0.18g/g$ creatinine, and that of toluene was $2.36{\pm}0.24g/g$ creatinine. Meanwhile, the results of the analysis of the control group showed that the exposure to benzene was $15.54{\pm}2.85mg/g$ creatinine, that of xylene was $0.52{\pm}0.02g/g$ creatinine, and that of toluene was $0.85{\pm}0.20g/g$ creatinine. The amount of exposure to benzene, xylene, and toluene was shown to be under the maximum permitted level, but as for Pathology department, it was required to educate on working conditions, to educate workers on prevention management about their health, and to install fume hood and exhaust system to improve the environments.

• Mass Spectrometry Letters
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• v.3 no.3
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• pp.74-77
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• 2012

Organic acid (OA) profiling analysis was performed in culture media from Lactobacillus pentosus K34 (L. pentosus K34) and Pediococcus lolli PL24 (P. lolli PL24) by gas chromatography-mass spectrometry (GC-MS) following methoxime/tert-butyldimethylsilyl derivatives. 12 OAs were positively identified in culture media. Most of OA levels from L. pentosus K34 of hetero lactic fermentation were found to be higher when compared with those from P. lolli PL24 of homo lactic fermentation, which may explain different OA metabolism in each strain. In addition, the distorted dodecagonal star patterns were readily distinguishable, and the characteristics of each strain were well represented. The present study demonstrates that the OA metabolic profiling method by GC-MS combined with star pattern recognition is useful for the monitoring study of characteristic OA metabolism in various microorganisms.