• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.4
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• pp.513-518
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• 2005

Volatile compounds of $\gamma-irradiation$ leeks (Aillum tuberosum R.) were isolated by simultaneous steam distillation and extraction method (SDE) and analyzed by gas chromatography/mass spectrometry (GC/MS) along with the non-irradiated sample. Leeks were irradiated at dose of 20 kGy and non-irradiated samples were considered as control sample. 56 and 54 compounds were identified in non-irradiated and irradiated samples, respectively. These components included the functional groups; alcohols, aldehydes, esters, ketones, N- and S-containing compounds. S-containing compounds such as dimethyl trisulfide, methyl-(Z)-l-proenyl trisulfide, dimethyl disulfide, 3-ethyl-l,2-dithi-5-ene and methyl allyl disulfide were the major compounds. Methyl-(Z)-l-propenyl trisulfide, diallyl trisulfide, (E)-2-hexanal and 3-ethyl-l,2-dithi-5-ene were clearly decreased by the $\gamma-irradiation$, but dimethyl disulfide, diallyl sulfide, allyl methyl sulfide and pyridine were increased by the $\gamma-irradiation$.

• Analytical Science and Technology
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• v.25 no.5
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• pp.273-283
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• 2012

Phthalate plasticizers are regulated by RoHS, REACH and CPSC as hazardous substances. Responding to these international environmental restrictions, we developed ABS certified reference material (CRM) for determination of phthalate plasticizers such as DMP, DEP, DBP, BBP, DEHP and DnOP. The candidate material has been made with ABS resin widely used in electric and electronic products and 6 kinds of phthalate plasticizers. The making of the material involved a series of processes like extruding, cooling, pelletizing, and drying using twin screw extruder. Then it has been certified according to ISO Guide 35. Using isotope dilution-gas chromatography/mass spectrometry (ID-GC/MS), homogeneity, short-term stability, and long-term stability were evaluated. The certified values were determined by using primary reference material (PRM) of KRISS for traceability. From now on, we will provide ABS CRM to national and international companies and research institutes after certification as certified reference material and registering on COMAR (code of reference material).

• Korean Journal of Food Science and Technology
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• v.43 no.3
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• pp.348-360
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• 2011

To verify the volatile compounds contributing to coffee off-flavor, medium roasted Colombian, Sumatra, Ethiopian and light and dark roasted Colombian bean coffees were sequentially and studiously over extracted. Eight espresso samples and eight filter-dripped samples were analyzed by gas chromatography/mass spectrometry with the solidphase microextraction method and evaluated by sensory tests. In total, 67 compounds were detected, and desirable aroma decreased sharply, while off-flavors increased rapidly after 30 mL of espresso and 200 mL of drip coffee. Percent peak area of 4-ethylguaiacol revealed a linear increase during extraction and was highly correlated with increasing off-flavor, suggesting that it could be an indicator of over extraction. Considering the odor activity value, guaiacol and 4- vinylguaiacol were also contributory compounds to off-flavors.

• Korean Journal of Environmental Agriculture
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• v.34 no.4
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• pp.294-302
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• 2015

BACKGROUND: Chemical accidents have increased owing to chemical usage, human error and technical failures during the last decades. Many countries have organized supervisory authorities in charge of enforcing related rules and regulations to prevent chemical accidents. A very important part in chemical accidents has been coping with comprehensive first aid tool. Therefore, the present research has provided information with the initial applications concern to the rapid analysis of hazardous material using instruments in vehicle of field mode after chemical accidents. METHODS AND RESULTS: Mobile measurement vehicle was manufactured to obtain information regarding field assessments of chemical accidents. This vehicle was equipped with four instruments including gas chromatography with mass spectrometry (GC/MS), Fourier Transform Infrared Spectroscopy (FT-IR), Ion Chromatography (IC), and UV/Vis spectrometer (UV) to analyses of accident preparedness substances, volatile compounds, and organic gases. Moreover, this work was the first examined the evaluation of applicability for analysis instruments using 20 chemicals in various accident preparedness substances (GC/MS; 6 chemicals, FT-IR; 2 chemicals, IC; 11 chemicals, and UV; 1 chemical) and their calibration curves were obtained with high linearity ( r ² > 0.991). Our results were observed the advantage of the high chromatographic peak capacity, fast analysis, and good sensitivity as well as resolution. CONCLUSION: When chemical accidents are occurred, the posted measurement vehicle may be utilized as tool an effective for qualitative and quantitative information in the scene of an accident owing to the rapid analysis of hazardous material.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.750-756
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• 2010

This study was performed to investigate the role of phytohormones in the bulbing of garlic in order to assess the yield and quality. The effect on endogenous plant hormones such as gibberellin (GA) content was also examined during growth stage i.e. clove differentiation to bulbing in garlic. More than 18 gibberellins in garlic were identified with extensive gas chromatograph-mass spectrometry-selected ion monitoring (GC-MS-SIM) quantitative analysis. The results showed that GAs were biosynthesized by both non C-13 hydroxylation pathway (NCH) and early C-13 hydroxylation pathway (ECH) in garlic plant. It was also revealed that NCH pathway leading to synthesis of bioactive $GA_4$ was the more prominent GA biosynthesis pathway than ECH pathway in which bioactive $GA_1$ was synthesized. Total GAs level was gradually increased from clove differentiation to bulbing and later decreased, which portrays the active role of GA in differentiation. The biosynthesis ratio of bioactive $GA_4$ and $GA_1$ concentration was similar to that of total GAs content, which was closely related with bulb development in garlic.

• Applied Chemistry for Engineering
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• v.28 no.1
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• pp.23-28
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• 2017

Pyrolysis characteristics of waste plastic films were investigated by using a thermogravimetric analysis and pyrolyzer-gas chromatography/mass spectrometry. Thermogravimetric analysis results revealed that the pyrolysis of waste plastic films can be divided into two distinct reactions; (1) the decomposition reaction of starch at between 200 and $370^{\circ}C$ and (2) that of other plastic polymers such as PS, PP, PE at between 370 and $510^{\circ}C$. The kinetic analysis results obtained by using the revised Ozawa method indicated that the apparent activation energy of the pyrolysis reaction of waste plastic films was also changed dramatically according to the different decomposition reactions of two major waste plastic film components. Py-GC/MS results also revealed that the typical pyrolyzates of each polymer in waste plastic films were levoglucosan (starch), terephthalic acid (PET), styrene monomer, dimer, and trimer (PS), methylated alkenes (PP), and triplet peaks (PE) composed of alkadiene/alkene/alkane. The phthalate, used as a polymer additive, was also detected on the pyrogram of waste plastic films mixture.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.120-124
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• 2007

Fusarium proliferatum KGL0401 was previously isolated from Physalis alkekengi var. francheti plant roots and exhibited higher GA productivity than wild type Gibberella fujikuroi. The :tim of this work was to find out an optimal culture condition for GA production. Various carbon(fructose, glucose, lactose, maltose, sucrose) and nitrogen($KNO_3$, urea, glycine, $NaNO_3,\;NH_4Cl$) sources were used for this study. GAs activities were analysed by gas chromatography and mass spectrometry(GC-MS). The highest yield of $GA_3$ was found in the growth medium supplemented with sucrose as carbon source and $NH_4Cl$ as nitrogen source. The optimum carbon-nitrogen concentration for $GA_3$ production was found to be 0.5 M:0.17 M. Supernatant was prepared from the culture fluid of F. proliferatum KGL0401 cultured for 7 days at 3 0'E and the 10 ul supernatant was treated with 2 leaf-rice seedling.

• Journal of Life Science
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• v.30 no.11
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• pp.973-982
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• 2020

In this study, we examined inhibition of adipocyte differentiation associated with the administration of camphor, a substance identified in extracts of the flowering plant Chrysanthemum indicum L. (CI). No camphor-mediated cytotoxicity was observed over a period of 1-10 days in studies targeting cells of the 3T3-L1 adipocyte-like line. Experiments that featured siRNA-mediated suppression of the transmembrane proteins Patched (PTCH) and Smoothened (SMO) resulted in inhibition and activation of differentiation, respectively. Interestingly, inhibition of PTCH typically activates SMO protein targeting and serves to activate hedgehog (HH)-mediated signaling. The results of our study suggest that activation of HH-mediated signaling can inhibit adipocyte differentiation. Furthermore, expression of glioma-associated oncogene homologue 1 (Gli1) was detected by flow cytometry in 62.7±1.5% of cells in response to administration of Lactobacillus rhamnosus (KCTC 3237) and in 60.4±2.2% of cells in response to camphor; these levels are higher than those detected in undifferentiated controls (24.9±3.1%). No change in the state of fermented camphor was identified by gas chromatography-mass spectrometry (GC-MS), but a 15.41% quantitative increase was confirmed in KCTC 3237. Overall, we conclude that administration of camphor resulted in overexpression of SMO and modulated the differential expression of Gli1. Animal studies focused on the impact of camphor as an agent to counteract obesity might be considered in the future. Indeed, camphor and similar physiologically active compounds from fermented CI might be developed as new and effective treatments for obesity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.1050-1056
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• 2000

To identify the irradiation-induced volatile flavor compounds, which were not detected in unirradiated sample and had positive correlation with the increment of irradiation dose, the volatile flavor compounds of irradiated (0, 1, 3, 5, 10 kGy) chicken were analyzed by liquid liquid continuous extraction (LLCE) and gas ehromatographyimass spectrometry (GC/MS) methods. One hundred twenty nine compounds were detected in irradiated chicken, and these compounds were composed mainly of hydrocarbons (62 compounds), aromatic compounds (44), aldehydes (9), ketones (5) and miscellaneous compounds (10). Among these, only 3 volatile compounds including 2-methylpentanal (r=0.24), 4-methylcyclohexene (r=0.08) and cyclotetradecene (r=0.92), were detected as irradiation-induced volatile flavor compounds in irradiated chicken. However, only cyclotetradecene was selected as a marker compound for detecting irradiation dosages with high correlation coefficient in irradiated chicken.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.1042-1049
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• 2000

Irradiation-induced volatile flavor compounds in irradiated (1, 3, 5, 10 kGy) beef were analyzed by liquid liquid continuous extraction (LLCE) and gas chromatography/mass spectrometry (GC/MS) methods. One hundred fifty volatile compounds were detected in irradiated beef. These compounds were composed mainly of 71 hydrocarbons, 35 aromatic compounds, 15 aldehydes, 7 ketones, 4 acids, 6 esters and 12 miscellaneous compounds. Among these, only 6 volatile compounds including (E) -2-hexenal, nonene, 2-nonenal, cyclodecene, dodecene and cyclododecene were detected as irradiation-induced volatile flavor compounds, comparing with unirradiated beef meat. However, 4 volatile compounds, such as cyclodecene (r=0.88), (E)-2-hexenal (r=0.85), nonene (r=0.74) and 2-nonenal (r=0.70), having a positive correlation coefficient with the increment of irradiation dose, were considered as marker compounds for detecting irradiation dosages in irradiated beef.