• Bulletin of the Korean Chemical Society
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• v.12 no.1
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• pp.87-92
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• 1991

A dual capillary column system is described for the simultaneous measurement of retention index (RI) and area ratio (AR) values of each peak on two capillary columns of different polarity, DB-5 & DB-1701. Both capillary columns were connected to a common splitless injector via a deactivated fused-silica capillary tubing of 1 m length and a 'Y' splitter, the dead volume effect of which was found to be negligible. RI and AR were measured with high reproducibility(${\leq}$0.05% RSD) and with high accuracy (<10% RE), respectively. When applied to the test samples of the organic acid mixture, each acid was positively identified by the combined computer RI library search-AR comparison.

• Analytical Science and Technology
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• v.25 no.6
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• pp.460-466
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• 2012

An environmentally friendly, so-called green, high performance liquid chromatography method was developed and validated for the determination of trans, trans-muconic acid (t,t-MA) in human urine as a biomarker of benzene exposure. After urinary t,t-MA was extracted and enriched using solid-phase extraction, a MF-Ph1 SG80 ($150mm{\times}2.0mm$ I.D., 5 ${\mu}m$) column with a mobile phase of 10 mM $KH_2PO_4$ containing 0.1% $H_3PO_4$ was used for isocratic separation of t,t-MA with UV detection at 259 nm. The calibration curve was constructed in the range of 0.1-5.0 mg/L with good linearity ($r^2$=0.9992). The intra-day and inter-day precision (as RSD) were 0.9-8.5% and 3.1-4.5%, respectively. The average recovery ranged from 97.5% to 101.7%. The green sample preparation and separation with no organic solvents were successfully achieved. The validated method would be suitable for the routine biological monitoring of benzene exposure in the occupational settings.

• Food Science and Biotechnology
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• v.17 no.4
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• pp.787-793
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• 2008

A major polyphenolic compound extracted from omija (Schisandra chinensis) fruit was structurally identified, and its composition of major nutrients was investigated as well in this study. A dominating high performance liquid chromatography (HPLC) peak of water-extracted anthocyanin represented 94.1% of total absorbable compounds at 520 nm, which was further identified with HPLC-mass spectrometry (MS). As a result, mass-to-charge ratio (m/z) of the predominant anthocyanin was determined to be 727, and it was identical to molecular mass of cyanidin-3-xylosylrutinoside (Cya-3-O-xylrut). This is the first report that colorant of omija is predominantly composed of Cya-3-O-xylrut. Omija fruit contained exclusively 3 types of monosaccharide such as glucosc (0.68 g), galactose (0.01 g), and fructose (0.52 g) per 100 g of fruits. Several organic acids, citric (3.29 g), malic (1.4 g), acetic (0.4 g), and succinic acids (0.36 g) per 100 g of fruits, were detected by high performance anion exchange chromatography (HPAEC) analysis. During the compositional analysis of tree amino acid by HPLC, it was noticed that omija fruit contained substantial amount (0.01 g/100 g of fruits) of $\gamma$-amino butyric acid (GABA).

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.9
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• pp.1471-1476
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• 2005

The optimization of ethanol treatment was carried out by response surface methodology (RSM) which was expressed through change of ${\Delta}$E value for improvement of color of dried large anchovy. The optimum condition was shown as treatment with 7 volumes (v/m) of ethanol at $50^{\circ}C$ for 9 hrs. At this condition, the removal rates of trimethylamine (TMA) and fat considered as fishy odor-causing materials were 81.1 and $77.4\%$, respectively, when analyzed by solid phase microextraction (SPME)/gas chromatography and soxhlet method, respectively The effect of citric acid on the removal rate of TMA was the highest one among organic acid treatments. The removal rate of TMA was affected greatly by the concentration of organic acid rather than the temperature and time of treatment. $73\%$ of TMA was removed by treatment of $1\%$ of citric acid at $20^{\circ}C$ for 20 min. Specially, above $90\%$ of TMA could be removed by the combination of alcohol and citric acid treatment. In vitro absorption rate of calcium was also increased to $12.3\%$ by the combination of alcohol and citric acid treatment compared with $2.9\%$ of control.

• Journal of the Korean Chemical Society
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• v.55 no.5
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• pp.751-755
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• 2011

A doubly tethered chiral stationary phase (CSP) based on (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid was applied to the resolution of various aryl ${\alpha}$-aminoalkyl ketones with the use of 80% ethanol in water containing 10 mM sulfuric acid as a mobile phase. The chiral resolution was quite successful, the separation factors (${\alpha}$) and the resolutions ($R_S$) being in the range of 1.39-2.05 and 3.18-5.22, respectively. The separation factors (${\alpha}$) on the doubly tethered CSP were slightly worse than those on the corresponding singly tethered CSP. However, the resolutions ($R_S$) on the doubly tethered CSP were generally greater than those on the corresponding singly tethered CSP. The chromatographic behaviors for the resolution of aryl ${\alpha}$-aminoalkyl ketones on the doubly tethered CSP were demonstrated to be dependent on the type and the content of the organic and acidic modifiers in aqueous mobile phase and the column temperature.

• Biomedical Science Letters
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• v.23 no.4
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• pp.388-394
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• 2017

Recently, coffee is the most popular beverage for modern people. A great number of substances are found in coffee beans and have been studied for many years such as aliphatic and aromatic compounds. However, studies on the physiological activity of coffee extracts are insufficient. This study was performed to determine the contents of caffeine and chlorogenic acid in coffee extracts according to the solvent and to investigate the physiological activity of coffee extracts. Coffee extracts were extracted by ultrasonication method with various types of solvents including distilled water, ethanol, and other organic solvents under $50^{\circ}C$ and $80^{\circ}C$. The contents of caffeine and chlorogenic acid in coffee extracts were determined by Liquid Chromatography-Mass Spectrometry (LC-MS). Also, cytotoxic and antioxidative effects of coffee extracts were evaluated with MTT and DPPH assays to analyze the physiological activity. As a result, it was confirmed that caffeine and chlorogenic acid contents were extracted in distilled water with the highest rate. Antioxidative activity was observed below 10-fold dilute of coffee extracts, however cytotoxicity was not observed. In conclusion, distilled water was the best solvent for extracting caffeine and chlorogenic acids from coffee bean with ultrasonication and these coffee extracts are less cytotoxic in human skin cell lines and have antioxidant effect.

• The Journal of Korean Medicine
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• v.21 no.1
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• pp.11-19
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• 2000

The present study was carried out to investigate the effects of Woowhangcheongshim-won(WCW) on the extracellular concentrations of amino acid neurotransmitters(glutamate, aspartate, GABA, glycine, taurine, alanine, and tyrosine) and organic acid (lactate and pyruvate) in striatum and cerebral infarction volume in rats subjected to permanent focal cerebral ischemia induced by 2 hours of middle cerebral artery occlusion(MCAO), using intracerebral microdialysis as the sampling technique, Microdialysis probes were inserted into the lateral part of the caudate-putamen 2 hours before the experiment and microdialyzates were collected at 20min intervals and analyzed by high performance liquid chromatography, WCW significantly decreased the infarction volume with reducing focal cerebral ischemia-induced increase of extracellular glutamate, asparate, and tyrosine. On the other hand, the increase of GABA and taurine was enhanced after treatment of WCW in the ischemia-induced rats, These results suggest that WCW can produce a neuroprotective effect against cerebral ischemia by regulating extracellular excitatory and inhibitory amino acid levels in relation to the concept of excitotoxicity in brain ischemia.

• Journal of Life Science
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• v.5 no.4
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• pp.170-180
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• 1995

A carotennnoprotein from the skin of Ascidian(Halocynthia roretzi) was extracted by Triton X-100 and purified by ammonium sulfate fraction, SephadexG-200 charomatography and DEAE-cellulose ion exchange chromatography. The carotenoprotein was redwith broad $\lambda$$_{max}$ between 495, 467 and 318nm. The red carotenoprotein had an approximate molecular weight of 326KDa(gel filtration). SDS-PAGE indicated the presence of two polypeptodes of 84.1KDa and 74.4KDa, with different mobility in polyacrylamide gel electrophoresis. In the presence of denaturing agents such as organic solvent aand extreme pH, the red complex readily disociates to liberate the yellow carotenoid($\lambda$$_{max}$ 452nm) and a colourless apoprotein. The amino acid composition of carotenoprotein were mainly threonine(15.2%), aspartic acid(12.2%), glutamic acid(11.9%) and serine(9.6%), while proline was not found. The carotenoprotein consisted of lipids as structure units. Its major fatty acids composion were C$_{18:1}$, C$_{16:1}$, and C$_{16:0}$. The monounsaturated fatty acids(41.5%) contained abundant content compared to other fatty aacids(polyunsaturated fatty acids 37.4%, saturated fatty acids 20.6%).

• Fire Science and Engineering
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• v.28 no.5
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• pp.71-79
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• 2014

This study was performed to test the combustive properties of Medium Density Fibreboards (MDFs) treated with chemicals of the bis-(dimethylaminomethyl) phosphinic acid (DMDAP), N,N-dimethylethylenediaminomethyl-bis-phosphonic acid (DMDEDAP), piperazinomethyl-bis-phosphonic acid (PIPEABP), and methylpiperazinomethyl-bis-phosphonic acid (MPIPEABP). MDFs were painted in three times with 15 wt% solution of the bis-(dimethylaminomethyl) phosphinic acid and alkylenediaminoalkyl-bis-phosphonic acids at the room temperature, respectively. After drying MDF treated with chemicals, combustive properties and volatile organic compounds (VOCs) contents were examined by the cone calorimeter (ISO 5660-1), test for flame retardant (NEMA Notice No. 2012034), and gas chromatography (KS M ISO 11890-2), respectively. It was indicated that the MDFs treated with chemicals showed the longer time to combustion time (CT) = (442~492) s than that of virgin plate by reducing the burning rate except for CT treated with DMDAP. In adition, the MDFs treated with chemicals showed both of the higher char area (44.33~61.33) kg/kg and char length (10.33~11.67) cm than those of virgin plate. Especially, the MDFs treated with chemicals showed the higher mean volatile organic compounds (VOCs) (0.188~0.333) g/L than that of virgin plate within the prescribed limits. Thus, It is supposed that the combustion- retardation properties were improved by the partial due to the treated chemicals in the virgin MDF.

• Applied Biological Chemistry
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• v.38 no.3
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• pp.263-268
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• 1995

A study was undertaken to compare degradation patterns of carbofuran in soils between submerged and upland moisture conditions [$3-^{14}C$]Carbofuran was treated in each soils at the rate of 1.0 mg/kg (87.8 kBq $^{14}C/50g$ soil) and the time-course analysis for distribution of radioactivity and degradation products were conducted. Differences in the pathway and rate of carbofuran degradation in soils were observed between submerged and upland moisture conditiona major degradation being hydrolysis at 7-C position and oxidation at 3-C position, respectively. Carbofuran showed less persistence in soils of higher moisture contents A significant portion, $24{\sim}39%$ of the total radioactivity, resided in soils as nonextractable residues at 60 days after treatment The nonextractable radioactivity was mainly located in soil organic matter, fulvic acid, humic acid and humin factions Gel filtration chromatography confirmed the incorporation of carbofuran and its degradation products into the organic matter.