• Korean Journal of Pharmacognosy
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• v.7 no.3
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• pp.159-169
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• 1976

The present review records the known structures of more than 80 organic compounds containing halogens, which may be considered naturally occurring. The format of the review is based on the viewpoint of biochemists. Compounds containing one type of halogen atom have been placed in one of four major division, i.e., structures possessing fluorine, chlorine, bromine or iodine covalently bonded to carbon. Within each major division molecular structures are given along with the species from which the compounds have been isolated, The biological significance, if any, is also mentioned.

• Journal of the Korean Chemical Society
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• v.11 no.2
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• pp.45-50
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• 1967

Radio thin layer chromatography of organic halogen compounds by neutron irradiation technique was investigated for the purpose of identifying and separating the mixture of halogen compounds. It was found that various halides, organic acids, and aldehyde gave a distinct developing peak both in cases of individual compound and a mixture of two or three components when the samples were developed by solvent methanol. But poly chlorinated compounds and aromatic or alicyclic chlorides gave more than one component peak when the sample was developed after neutron irradiation. Rf value of each compound was distinct and reproducible. The procedures were described and validity of the present method is discussed.

• Bulletin of the Korean Chemical Society
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• v.28 no.1
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• pp.59-62
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• 2007

A quantitative analysis method of halogen elements in volatile organohalogen compounds was established by the Wickbold combustion pretreatment in an enclosed system and ion chromatography. The sample pretreatment parameters of Wickbold combustion were experimentally optimized, and using the determined optimal pretreatment parameters, the reproducibility was estimated by ion chromatography. As a comparison for real samples, NIST certified reference materials (CRMs) were analyzed for the recovery efficiency and reproducibility.

• Journal of Environmental Science International
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• v.13 no.3
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• pp.205-214
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• 2004

This study focuses on the measurement of airborne Volatile Organic Compounds (VOCs) in the Kumi electronic industrial complex during the time periods of August and September, 2002 and January and February, 2003. This study was based on the US-EPA method TO-14 while the VOCs were analyzed with GC/MSD. The toluene level revealed high concentration at all measurement sites. The areal rank of average concentrations of VOCs is as follows: industry1 > industry2 > urban > middle > residential. Concentrations of VOCs in Kumi electronic industrial ones were generally higher than at Yeochon and Ulsan industrial complexes. Dichloromethane and trichloroethylene, which are used as a cleaner in the process of electronic industries, were observed 4 to 8 times higher than those of other areas. Among the aromatic compounds, toluene showed the highest level, while the concentrations of dichloromethane and trichloroethylene were higher than those of other halogen compounds. In Kumi, toluene, trichloroethylene, and dichloromethane were confirmed as the major compounds of VOCs by this research.

• Environmental Analysis Health and Toxicology
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• v.17 no.3
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• pp.197-205
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• 2002

Volatile organic compounds (VOCs) are an important public health problem throughout the world. Many important questions remain to be addressed in assessing exposure to these compounds. Because they are ubiquitous and highly volatile, special techniques must be applied in the analytical determination of VOCs. Personal exposure measurements are needed to evaluate the relationship between microenvironmental concentrations and actual exposures. It is also important to investigate exposure frequency, duration, and intensity, as well as personal exposure characteristics. In addition to air monitoring, biological monitoring may contribute significantly to risk assessment by allowing estimation of absorbed doses, rather than just the external exposure concentrations, which are evaluated by environmental and personal monitoring. This study was conducted to establish the analytic procedure of VOCs in air, blood, urine and exhaled breath and to evaluate the relationships among these environmental media. The subjects of this study were selected because they are occupationally exposed to high levels of VOCs. Environmental, personal, blood, urine and exhalation samples were collected. Purge ＆ trap, thermal desorber, gas chromatography and mass selective detector were used to analyze the collected samples. Analytical procedures were validated with the“break through test”, 'quot;recovery test for storage and transportation”,“method detection limit test”and“inter-laboratory QA/QC study”. Assessment of halogenated compounds indicted that they were significantly correlated to each other (p value < 0.01). In a similar manner, aromatic compounds were also correlated, except in urine sample. Linear regression was used to evaluate the relationships between personal exposures and environmental concentrations. These relationships for aromatic and halogenated are as follows: Halogen $s_{personal}$ = 3.875+0.068Halogen $s_{environmet}$, ($R^2$= .930) Aromatic $s_{personal}$ = 34217.757-31.266Aromatic $s_{environmet}$, ($R^2$= .821) Multiple regression was used to evaluate the relationship between exposures and various exposure deter-minants including, gender, duration of employment, and smoking history. The results of the regression model-ins for halogens in blood and aromatics in urine are as follows: Halogen $s_{blood}$ = 8.181+0.246Halogen $s_{personal}$+3.975Gender ($R^2$= .925), Aromatic $s_{urine}$ = 249.565+0.135Aromatic $s_{personal}$ -5.651 D.S ($R^2$ = .735), In conclusion, we have established analytic procedures for VOC measurement in biological and environmental samples and have presented data demonstrating relationships between VOCs levels in biological media and environmental samples. Abbreviation GC/MS, Gas Chromatography/Mass Spectrometer; VOCs, Volatile Organic Compounds; OVM, Organic Vapor Monitor; TO, Toxic Organicsapor Monitor; TO, Toxic Organics.

• Journal of Environmental Science International
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• v.8 no.2
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• pp.233-240
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• 1999

Industrial waste which highly loaded by halogenide phenols was photooxidized by laboratory-scale photooxidation of these organic impurities in the presence of aerotropic and titaniumdioxide as photocatalyst. The disapperance of organic compounds was determined as a function of the irradiation time. Some contaminants such as 2-chlorophenol, 2-bromphenol, 3-bromphenol, 4-bromphenol, 2,4-dibromophenol and 2,6-dibromophenol were photodegraded separately to obtain information on the reaction rates, reactivities, and reaction mechanisms of the photooxidation, and on the stoichiometric correlation between organic reactant and inorganic products concentration in the course of the photocatalytic photoreaction.

• Journal of the Korean Chemical Society
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• v.18 no.5
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• pp.363-367
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• 1974

Approximate rate and stoichiometry of the reaction of ten compounds which contain functional group such as nitrile, nitro, halogen and one of these functional group together with a carbonyl group by the two phase reduction were tested at room temperature. Nitrile, nitro and halogen were all inert under these condition. Therefore selective reduction of carbonyl group in the presence of these group were examined. Thus m-nitrobenzaldehyde, m-nitroacetophenone, p-bromoacetophenone and p-cyanobenzaldehyde were reduced to corresponding alcohols in excellent yields, 95∼100 %.

• Journal of the Semiconductor & Display Technology
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• v.18 no.4
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• pp.35-39
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• 2019

Effect of Ge₂Sb₂Te₅ (GST) chalcogen composition on plasma induced damage was investigated by using Ar ions and F radicals. Experiments were carried out with three different modes; the physical etching, the chemical etching, and the ion-enhanced chemical etching mode. For the physical etching by Ar ions, the sputtering yield was obtained according to ion bombarding energy and there was no change in GST composition ratio. In the plasma mode, the lowest etch rate was measured at the same applied power and there was also no plasma induced damage. In the ion-enhanced chemical etching conditions irradiated with high energy ions and F halogen radicals, the GST composition ratio was changed according to the density of F radicals, resulting in higher roughness of the etched surface. The change of GST composition ratio in halogen plasma is caused by the volatility difference of GST-halogen compounds with high energy ions over than the activation energy of surface reactions.

• Bulletin of the Korean Chemical Society
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• v.17 no.4
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• pp.380-384
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• 1996

Lithium trimethylalkynylaluminates, prepared conveniently by reacting trimethylaluminum with lithium alkynide, readily react with aldehydes and ketones to give the corresponding propargyl alcohols in 70-95% yields. The reaction is highly chemoselective; thus many other functional groups such as amides, nitriles, epoxides and halogen compounds are inert under the reaction conditions. The reagents also show an excellent 1,2-regiospecificity in the reactions with cyclic or acyclic α,β-unsaturated carbonyl compounds.

• Journal of the Korean Chemical Society
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• v.8 no.2
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• pp.47-56
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• 1964

When a developed paper partition chromatogram was irradiated by means of the pneumatic tube system of the Korean research reactor (neutron flux: 1.5 ${\times}10^{12}n/cm^2$sec.) the qualitative confirmation of the developed spot on the chromatogram was possible. In the case of an organic halogen compounds (chloro-acid, chloro-ester, iodide, and fluoride) the spot analysis was possible by the present method whereas the same spot could not give the distinct coloring with a common coloring reagents. Filterpaper thickness calibration and activity calibration induced by irradiation of the components of the filter paper, which were a source of erraneous interpretation of the spot, were searched and an average filterpaper calibration method and filter paper activity were improvised to obtain a good qualitative analysis of the spot. Finally the use and applicability of this method for the analysis identification of an organic halogen compound were evaluated. As the filter paper phase an ordinary phase (Whatmann #1, filter paper) and reversed phase (liquid paraffin impregnated) were used.