• Journal of Korean Society of Environmental Engineers
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• v.35 no.12
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• pp.906-917
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• 2013

The purpose of this study is to quantify volatile organic compounds (VOCs) in gas sample using headspace solid-phase microextraction (HS-SPME) coupled to GC analysis. The optimal HS-SPME conditions was CAR/PDMS fiber and 30 min absorprion time for the analysis of various VOCs. In optimal conditions, 80 VOCs could be detected within 1 ppbv and even less than 0.0005 ppbv especially in the case of BTEX. However, fiber reproducibility on adsorption efficiency was 1~9.2% (between the same fiber) and 5.9~13.5% (between the other fiber). We successfully determined 35 VOCs in landfill gas with this method and found that VOCs of high concentration are emitting from vent pipe of closed/open landfill site under the HS-SPME conditions. This method may apply to VOCs/odor determination from various atmospheric environmental samples as well as landfills.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.6
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• pp.734-745
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• 2011

In this article, we reviewed the monitoring status of hazardous VOC in ambinet air in Korea and some developed countries such as USA, Japan, and UK. In many countries, two types of VOC monitoring stations are being operated, i.e., for hazardous VOC and photochemical VOC. Each country has different target VOC but all includes benzene. Korea, Japan, and UK have a national ambient air quality standard for benzene, but no national standard has been established in the USA. For sampling of the hazardous VOC, the adsorbent method is adopted in Korea and UK, while the canister method is used in the USA. Both of adsorbent and canister methods are used in Japan. USA and UK have only non-automatic method to measure the hazardous VOC, and the individual samples are being sent to their national laboratories for integrated analysis. On the other hand, Korea and Japan have automatic and nonautomatic methods to measure the hazardous VOC. Local governments or regional environmental agencies in Korea and Japan have the authorization for the sampling and analysis of VOC. According to a field study to evaluate the performance of automatic VOC monitoring system, controlling the moisture in the air sample was identified as the most important problem. However, careful attention must be given to using a moisture removing device such as Nafyon dryer, because of unexpected artifacts formation. In order to have reliable data, it is highly recommended not only to use internal standards, but to use appropriate hydrophobic adsorbents as a cold trap in any automatic on-line VOC monitoring system.

• Korean Journal of Environmental Biology
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• v.38 no.1
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• pp.61-70
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• 2020

A eukaryotic microalga was isolated from seawater in Janghang Harbor, Korea and its morphological, molecular, and physiological characteristics were investigated. Due to its simple morphology, no distinctive characters were found by morphological observation, such as light microscope or scanning/transmission electron microscopy (S/TEM). However, molecular phylogenetic evidence inferred from the concatenated small subunit (SSU) 18S rRNA and internal transcribed spacer (ITS) sequence data indicated that the isolate belonged to the newly described Micractinium singularis. Furthermore, it was clustered with Antarctic Micractinium strains and it also showed a psychrotolerant property, surviving at temperatures as low as 5℃. However, its optimal growth temperatures range from 15℃ to 25℃, indicating that this microalga is a mesophile. Additionally, gas chromatography-mass spectrometry (GC/MS) analysis showed that the isolate was rich in nutritionally important omega-3 polyunsaturated fatty acid, and high-performance liquid chromatography analysis (HPLC) revealed that the high-value antioxidant lutein was biosynthesized as an accessory pigment by this microalga, with glucose as the major monosaccharide. Therefore, in this study, a Korean marine M. singularis species was discovered, characterized, and described. It was subsequently added to the national culture collections.

• Journal of the Korean Society of Tobacco Science
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• v.31 no.1
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• pp.39-44
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• 2009

Hydrogen cyanide (HCN) is present in both the particulate and vapor phase of cigarette mainstream smoke. It is one of the 44 harmful substances on Hoffmann's list and is known to be a major ciliatoxic agent in cigarette mainstream smoke. Typically the determination of HCN in cigarette mainstream smoke has been done through colorimetric and electrochemical techniques, such as UV-spectrophotometry (UV), continuous flow analyzer (CFA), ion chromatography (IC) and capillary GC-ECD. In particular, CFA commonly has been using analysis hydrogen cyanide in cigarette smoke and the basic principle is pyridine-pyrazolone reaction. In this study, the more optimized analytical method is suggested isonicotinic acid-pyrazolone reaction method than previous pyridine-pyrazolone reaction method, a commonly used method for the determination of cyanide in water and air, by CFA. Sample collection was optimized by trapping particulate and vapor phase of smoke separately. The optimum NaOH concentration of the trapping solution was shown to be 0.2 M. HCN was stable up to 6 hours in this concentration but only 3 hours in 0.1 M solution. The sensitivity of this method was fairly good and it might be used in analysis of HCN in cigarette mainstream smoke.

• Applied Biological Chemistry
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• v.43 no.2
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• pp.81-85
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• 2000

Screening was performed to isolate biopolymer-producing microorganisms from natural sources. The bacteriological characteristics of this strain and physicochemical properties of the biopolymer produced were investigated. The bacterial strain was identified as a Bacillus coagulans. Crude biopolymer treated with ethanol and actone was purified to fraction I and II by ion exchange chromatography and gel chromatography (Shephadex G-100 and Shepharose CL-2B). Analysis of chemical composition and various color reaction revealed that the polymer is composed of amino acids. It was confirmed that fraction II is a homopolymer of glutamic acid and fraction I is a homopolymer of lysine by analysis data of amino acid analyzer, GC and IR.

• Journal of Applied Biological Chemistry
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• v.49 no.3
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• pp.101-105
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• 2006

Degradation of the herbicide butachlor was investigated using laboratory-synthesized zerovalent iron ($Fe^0$). The synthesized zerovalent iron was determined to be nanoscale powder by scanning electron microscopic analysis. To investigate degradation of butachlor using the synthesized nanoscale zerovalent iron, time-course batch experiments were conducted by treating the solution of butachlor formulation with the iron. More than 90% degradation of butachlor was observed by iron treatment within 24 h. The synthesized nanoscale zerovalent iron showed an increase in particle aggregation in the batch tests. Green rust formation and a pH drop in solutions were observed, suggesting that the oxidation of the iron occurred. When the iron was extracted with dichloromethane, a negligible concentration was found in the extract, suggesting that butachlor did not bind to the iron particles. GC/MS analysis detected the dechlorinated product as a major degradation product of butachlor in the solutions. The data indicate that laboratory-synthesized zerovalent iron functioned as a reductant to remove electron-withdrawing chlorine, giving the dechlorinated product.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.2
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• pp.206-219
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• 2010

To establish the fundament for EBM of Traditional Korean Medicine, the papers on Sagunja-tang(Sijunzi-tang) frequently used in medical institutions of Traditional Korean Medicine were analyzed through researching domestic and international papers. The papers were classified by the registration of domestic or international journals, the year of publishment, experimental fields and the kinds of studies on biological activities. Of total 228 papers on Sagunja-tang(Sijunzi-tang), 121 volumes were selected according to creteria. 47 volumes were published in domestic journals, 71 in Chinese journal, 2 in Japanese journal, and 1 in Taiwan journal. The papers on instrumental analyses were preceeded by HPLC, MS, GC with standard compounds of herbal medicine in Sagunja-tang(Sijunzi-tang). The papers on biological activities of Sagunja-tang(Sijunzi-tang) showed improvement of gastrointestinal activity and blood circulation, immunoactivity, anti-cancer, anti-oxidant, anti-fatigue, anti-stress, pharmacokinetics, hepatic protection, radioprotection, muscular activity, hematopoiesis and nontoxical effect. Further studies including gastrointestinal disorder, immune related disease, cancer, oxidative injury and pharmacokinetic study need to be preceeded to establish the fundament for EBM of Sagunja-tang(Sijunzi-tang).

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.2
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• pp.414-424
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• 2007

Adenophorae Radix (AR), Liriopis Tuber (LT), Dendrobii Monile (DM), Polygonati Officinalis (PO), Polygonati Rhizoma (PR) have been used to treated a variety condition/diseases in traditional oriental medicine. The present study was conducted to investigate the immunmodulatory effects of the water-extracted AR, LT, DH, PO and PR. In spleen cell proliferation assay, DH was significantly enhanced mitogenic activity compared with control group. In RT-PCR, DH ad PO induced IL-2 and IFNr cytokine gene expression in mouse spleen cells. Methotrexate(MTX), immune supression agent, was significantly inhibited mouse spleen cell proliferation(1600 mg/ml). In spite of MTX treatement, DH and PO sustained the spleen cell proliferation, In the flow cytometry analysis, DH stimulated mouse spleen cells showed an increase in B-cell phenotype (CD45R/B220). The water-extracted DH and PO inhibited NO production and iNOS expression in LPS-stimulated RAW 264.7 macrophage cell. DH induced IL-2 and IFNg gene expression in human peripheral mononuclear cells. The GC-MS analysis show that the main component of water-extracted DH was b-Nitroethyl alcohol. The main components of water-extracted PO were Dipirartril-tropico, Methyl sulfoxide and Demsodrox. These data suggest that among these extracts, DH has a protective effcet of immune suppression caused by MTX. DH may be enhance cellular and humoral immune response by the regulation of cytokine gene expression, NO production and B cell production.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.1
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• pp.64-69
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• 2016

This study was conducted to develop a fast and efficient screening method to determine the quantity of fatty acid in peanut oil for high oleate breeding program. A total of 329 peanut samples were used in this study, 227 of which were considered in the calibration equation development and 102 were utilized for validation, using near infrared reflectance spectroscopy (NIRS). The NIRS equations for all the seven fatty acids had low standard error of calibration (SEC) values, while high R2 values of 0.983 and 0.991 were obtained for oleic and linoleic acids, respectively in the calibration equation. Furthermore, the predicted means of the two main fatty acids in the calibration equation were very similar to the means based on gas chromatography (GC) analysis, ranging from 36.7 to 77.1% for oleic acid and 7.1 to 42.7% for linoleic acid. Based on the standard error of prediction (SEP), bias values, and $R^2$ statistics, the NIRS fatty acid equations were accurately predicted the concentrations of oleic and linoleic acids of the validation sample set. These results suggest that NIRS equations of oleic and linoleic acid can be used as a rapid mass screening method for fatty acid content analysis in peanut breeding program.

• Journal of the Korean Society of Food Culture
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• v.12 no.2
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• pp.173-182
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• 1997

This study was carried out in order to investigate effective aroma components of Korean traditional soy sauce. Volatile aroma compounds were extracted by solvent extraction, TMS esterification of methyl acetate extracts and SDE, and analyzed by GC/MSD. 140 voltile aroma compounds were detected by three different extraction methods. Most abundant volatile compounds were acids and phenols and identified aldehydes, hydrocarbons, ketones, furans, furanone, alcohols, esters, nitrogen compounds, sulfur compounds and thiazoles, too. In the analytical sensory evaluation of soy sauce aroma, there were significant differences between each soy sauce sample in all test item. To sum up, Sweet odor was high in Kyupjang. Nutty odor and traditional soy sauce odor were similarly high in Kyupjang and high concentration soy sauce. Kyupjang had high score in overall odor preference than Chungiangs. The result of multiple regression of soy sauce odor characteristics and gas chromatography pattern demonstrated that offensive and sour odor was affected by octadecanoic acid. Contributive compounds to sweet odor were 1,2-benzenedicarboxylic acid and 3,6-dioxa-2,7-disilacotane. Benzoic acid 4-methyl ethyl ester and nonacotane were identified as major compounds of nutty odor. Contribu live variables of traditional soy sauce odor were benzoic acid 4-methyl ethyl ester and 9,12-octadecadienoic acid. The main factors of odor preference were 3-methyl pentanoic acid, acetic acid, 2,6-dimethyl heptadecane and 3,6-dioxa-2,7-disilacotane.