• Journal of Environmental Science International
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• v.5 no.5
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• pp.561-567
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• 1996

A method for the simultaneous analysis of 31 residual organic chloride pesticides was studied using gas chromatography. Prepared analytical samples were injected to gas chromatography (HP 5890 Series II plus) on the Ultra-2 column with ECD. The packing materials for column were changed as the following reagents ; florisil and alumina N, The residual solution was loaded to column and was elected pith erection solvents ; ether : benzene (2 : 8) solution, hexane : benzene (1 : 1) solution, dichloromethane, acetone, and methanol. The analytical results showed that 6 kinds of organic chlorides were not detected when florisil (first condition) was used as the column packing material. The nondetected 6 kinds of organic chlorides in the first analytical condition were detected and the recoveries of thrin-pesticides were increased, in particular, captan and captafol, but the recoveries of benzene hexachloride compounds were decreased when dichloromethane and methanol were added as elution solvents (pac'king material was florisil as in the first condition). The recoveries of dichlornuanid, chlorofenvinfos, folpet, and dicofol were increased and that of aldrin was increased, but those of captan and captafol were not good when alumina N was used as the packing material. To detect simultaneously thrin-pesticides, captan, and captafol, florisil and alumina N were used as the packing materials. The elution result showed that captan and captafol were not detected. This was because the column was activated insufficiently. The analytical method was the best (31 kinds of organic chlorides in the residual pesticides were detected sharply and showed high sensitivity) when the column (packing materials were florisil and alumina N: together) was fuliy activated and the impurities were removed using various elution solvents.

• Applied Biological Chemistry
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• v.44 no.4
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• pp.262-268
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• 2001

Two commercial wood vinegar liquors prepared from Cryptomeria japonica and Quercus sp., which are used as a mineral fertilizer in Korea, were extracted using dichloromethane as a solvent, respectively. The extracts were separated into acidic, phenolic, neutral and basic fraction by acid or alkali treatment, and the compositions of each fraction were analyzed by means of GC and GC-MS. A total of 103 compounds including 26 acids, 32 phenols and 45 neutral compounds were identified. The major components were acetic, propionic and n-butyric acid, representing of $41{\sim}58%$ of the acidic fraction, guaiacol, 4-methylguaiacol and phenol, repersenting of $53.2{\sim}63.9%$ of the phenolic fraction, and furfural, 3-methyl-2-cyclopenten-2-one, 2,3-dimethyl-2-cyclopenten-1-one and 5-methyl-2-furfural in the neutral fraction. In addition to these compounds, phenolic fraction in dichloromathane extract from wood vinegar liquor of C. japonica included large amounts of vanillin, acetovanillone and tentatively identified ethylvanillyl ether while that of Quercus sp. included some amounts of syringol and 4-methylsyringol.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.7
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• pp.819-824
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• 2007

The present study describes the cytotoxic effect of Artemisia fukudo extracts. The extract from A. fukudo by 80% ethanol was fractionated with n-hexane, dichloromethane, ethylacetate, and butanol in serial. The cytotoxicity of A. fukudo extracts was examined for its effect on the growth of HL-60 cells by the colorimetric 3-(4,5-dimethylthiazol)-2,5-diphenyltetrazolium bromide (MTT) assay. In addition, we used the HL-60 cells to see what effects the A. fukudo extracts will have on apoptosis of cancer cells. We checked the cell activity, cell morphologic changes, DNA fragmentation, and DNA content after 24 hr incubation with administering 25 ${\mu}g/mL$ of the A. fukudo extracts. In the treatment of the low concentration of n-hexane and dichloromethane fractions, the survival rate of HL-60 cells is lower than that of the control. The laddering-pattern DNA fragmentation was observed in the treatment with n-hexane and dichloromethane fractions. The DNA content of the cells apoptosis measured as the density of sub-$G_{1}$ hypodiploid cells by flow cytometric analysis. The number of sub-$G_{1}$ hypodiploid cells increased in the treatment with n-hexane and dichloromethane fractions. These fractions obstructed the cell cohesion and caused the blebbing of the cell membrane and fragmentation of the nucleus, both of which are symptoms of apoptosis. These results suggest that A. fukudo has a great potential value as food additives, medicinal supplements for patients with chronic diseases, and preventive measures against cancer.

• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.304-307
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• 2005

Multiresidue method was set up for the simultaneous determination of various residual pesticides in potatoes and carrots, which was analyzed by gas chromatography-electron capture detector/nitrogen phosphorus detector. Method consisted with acetone/acetonitrile (9 : 1) extraction and dichloromethane partition, followed by florisil cartridge purification with hexane/dichloromethane/acetonitrile (50 : 45 ; 5) elution. Among 197 pesticides (194 kinds) spiked to food materials, 143 and 155 pesticides were recovered over 70% on potatoes and carrots, respectively. Nineteen pesticides including bromacil, cyproconazole, were not detected in water and sample matrices. Matrix components may affect the low detections of 25 pesticides such as benfuracarb, bitertanol from potatoes and 16 pesticides such as bitertanol, carbosulfan from Carrots. Some pesticides including dichlobenil, fluoroimide and iprodione were highly detected from one or both matrices even though they were not detected from water.

• Journal of Environmental Health Sciences
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• v.36 no.5
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• pp.391-401
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• 2010

A reduction in risk of occupational exposure to chemical hazards within the workplace has been the focus of attention both through industry initiatives and legislation. The aims of this study were to develop an exposure matrix by industry and process, and to apply this matrix to control the risk of occupational exposure to Dichloromethane (DCM). The exposure matrix is a tool to convert information on industry and process into information on occupational risk. The exposure matrix comprised industries and processes involving DCM, based on an exposure database provided by KOSHA (the Korean Occupational Safety and Health Agency), which was gathered from a workplace hazards evaluation program in Korea. The risk assessment of the exposure matrix was performed using Hallmark risk assessment tool. The results of the risk assessment were indicated by a Danger Value (DV) calculated from the combination of hazard rating (HR), duration of use rating (DUR), and risk probability rating (RPR) of exposure to the chemical, and were divided into four control bands which were related to control measures. The applicability of the risk assessment of the exposure matrix was evaluated by a field study, and survey of the employees of the exposure matrix groups. Among 45 industries examined, this study found that greater attention should be paid to two industries: the manufacture of other optical instruments and photographic equipment, and the manufacture of printing ink, and to one process among 47 examined, the packing process in the manufacture of printing ink, because these were regarded as carrying the highest risk. This tool of a risk assessment for the exposure matrix can be applied as a general exposure information system for hazard control, risk quantification, setting the occupational exposure limit, and hazard surveillance. The exposure matrix includes workforce data, and it provides information on the numbers of exposed workers in Korea by agent, occupation, and level of exposure and risk.

• Korean Journal of Environmental Agriculture
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• v.40 no.2
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• pp.134-141
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• 2021

BACKGROUND: The analytical method was established for determination of fungicide chinomethionat in several animal commodities using gas chromatography (GC) coupled with electron capture detector (ECD). METHODS AND RESULTS: In order to verify the applicability, the method was optimized for determining chinomethonat in various livestock products including beef, pork, chicken, milk and egg. Chinomethionat residual was extracted using acetone/dichloromethane(9/1, v/v) with magnesium sulfate and sodium chloride (salting outassociated liquid-liquid extraction). The extract was diluted by direct partitioning into dichloromethane to remove polar co-extractives in the aqueous phase. The extract was finally purified with optimized silica gel 10 g. CONCLUSION: The method limit of quantitation (MLOQ) was 0.02 mg/kg, which was in accordance with the maximum residue level (MRL) of chinomathionate as 0.05 mg/kg in livestock product. Recovery tests were carried out at two levels of concentration (MLOQ, 10 MLOQ) and resulted in good recoveries (84.8~103.0%). Reproducibilities were obtained (Coefficient of variation <5.2%), and the linearity of calibration curves were reasonable (r²>0.995) in the range of 0.01-0.2 ㎍/mL. This established analytical method was fully validated and could be useful for quantification of chinomathionat in animal commodities as official analytical method.

• 대한치주과학회:학술대회논문집
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• 2004.11a
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• pp.165-165
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• 2004

• Journal of Photoscience
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• v.4 no.2
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• pp.49-52
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• 1997

Irradiation (300 nm) of 1, 2-benzoquinones 1 and diphenylacetylene 2 in dichloromethane yielded two isomeric quinone methides, 6 and 7. The same types of quinone methides, 9 and 10 (or 12 and 13) were obtained from the photocycloadditions of 9, 10-phenanthrenequinone 8 (or acenaphthenequinone 11) to diphenylacetylene 2. One-way photoisomerizations were observed between each isomeric adducts, (6, 7), (9, 10) and (12, 13).

• Bulletin of the Korean Chemical Society
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• v.8 no.4
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• pp.296-298
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• 1987

Irradiation of a solution of chloranil and cycloheptatriene, or 1,3-cyclohexadiene, in dichloromethane yielded unexpected photorearrangement products as the major product, while chloranil with cyclohexene gave the photorearrangement product as well as 1 : 1 adduct.

• Analytical Science and Technology
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• v.10 no.3
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• pp.168-178
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• 1997

The optimum conditions for the residual analysis of the ethalfluralin herbicide on soils were investigated and the residues in soils were determined by gas chromatography with electron capture detector(GC-ECD). The soil samples extracted with methanol and dichloromethane and concentrated. The concentrated phase were redissolved with toluene and analyzed with GC-ECD after separated by cyanosilica gel Sep-Pak cartridge. From the standard addition experiments with 0.1 and 1.0ppm, the average recoveries were 92.8~101.2% and the detection limit was 0.004ppm. The half-life time of ethalfluralin in the soil(A) was 35 days in the laboratory and 7.2 days in the field test whereas it was 45 days and 9.7 days for each in case of soil(B).