• Bulletin of the Korean Chemical Society
• /
• v.6 no.6
• /
• pp.337-343
• /
• 1985

A statistical mechanical approach to elucidate the solvent effects on the high polymer solutions has been carried out on the basis of the simple model of liquids improved by Pak. In our works, the partition function of the polymer solutions is formulated by the lattice model and our simple treatment of liquid structures. For the ideal polymer solutions proposed by Flory, thermodynamic functions of the polymer solutions are obtained and equations of mixing properties and partial molar quantities are derived from the presented partition function of the polymer solutions. Partial molar quantities are calculated for the rubber solutions in carbon disulfide, benzene and carbon tetrachloride. Comparisons have been made between our equations and those of Flory's original paper for partial molar properties of the rubber-benzene system. Comparing the experimental data of the osmotic pressure of polystyrene-cyclohexane system with our calculated values and those of Flory's, our values fit to the agreeable degrees better than those of Flory's.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.11 no.6
• /
• pp.496-502
• /
• 2006

Off-flavors and unfavorable odors in tuna fish oil were successfully removed and identified using supercritical carbon dioxide extraction, while retaining variable compounds, polyunsaturated fatty acids such as EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Samples of oil were extracted in a 100 mL semi-batch stainless steel vessel under conditions which ranged from 8 to 20 MPa and $20\;to\;60^{\circ}C$ with solvent ($CO_{2}$) flows from 10 g/min. GC-MS was used to identify the main volatile components contributing to the off-flavors and odors which included 2-methyl-1-propanol, 2,4-hexadienal, cyclopropane, and octadiene. Analyses of oil extracted at $40^{\circ}C$, 20 MPa showed a 99.8% reduction in dimethyl disulfide. Other significant off-flavors identified were 2-methyl-butene, 3-hydroxy butanal and ethylbenzene.

• Analytical Science and Technology
• /
• v.14 no.3
• /
• pp.274-285
• /
• 2001

In this study, the thermal desorption-cryofocusing-gas chromatographic(TD-C-GC) method was developed for determination of volatile organic compounds(VOCs) in ambient air and was applied at the municipal solid waste landfill sites. On-column cryofocusing was possible only with a 100 ml dewars bottle in TD-C-GC method with a stainless steel column. However, high operating pressure was needed for purging VOCs from the absorbent trap, which was able to solve by pressure programming with a electric pressure controller. By using both pressure and temperature programming brought increasing of resolution power in on-column cryofocusing method, but the high pressure caused a leakage of sample tube with repeated use. A loop cryofocusing devise was also developed and compared with the direct on-column method. In loop cryofocusing method, VOCs were concentrated on a 0.8mm i.d. loop which is located between the injector and separation column by using liquid nitrogen. In order to purge VOCs from the absorbent trap, only 0.4 psi of pressure was need in the loop cryofocusing method. Dual detection system was applied for the analysis of VOCs; a FID was used for hydrocarbons and a FPD was used for sulfur-containing compounds. Qualitative analysis was done by on-column cryofocusing GC-MS system. Among the large number of VOCs, toluene was the most abundant. Hydrogen sulfide, dimethyl sulfide, carbon disulfide, dimethyl disulfide and methyl propyl disulfide were detected at landfill site by FPD.

• Korean Journal of Food Science and Technology
• /
• v.20 no.5
• /
• pp.718-723
• /
• 1988

A yeast strain producing fruity-floral aroma was isolated from soil and identified as Hansenula saturnus var. saturnus. Glucose was found to be the best carbon source and sodium nitrate or phenylalanine as nitrogen source in terms of the nature and the intensity of the aroma produced by the isolated yeast. Seventeen compounds, mainly esters and alcohols, were identified in the ether-pentane extract of the culture broth by gas chromatography and/or coupled gas chromatography-mass spectrometry. Ethyl alcohol, isobutyl alcohol, isoamyl alcohol, phenethyl alcohol and their acetate esters together with ethyl caprylate were the major compounds in the aroma concentrate. Three unusual compounds, dibutyl disulfide, 3-methyl pentanoic acid and methyl pentanoate were also tentatively identified in the culture broth of the isolated yeast.

• Archives of Pharmacal Research
• /
• v.12 no.2
• /
• pp.119-124
• /
• 1989

Cotton xanthate, which was obtained by treating cotton with carbon disulfide in alkaline solution, was treated with the solution of polyvalent metal ions to produce cotton xanthate-metal chelates. This chelation reaction was readily and simply achieved, and antimicrobial agents with suitable structures could subsequently be coupled to the chelate with ease at moderate pH values and in aqueous solution. Metal ions used in present work include Cu(II), Zn(II) and Fe(III). Tetracycline, streptomycin, neomycin and pyrithion were used as antimicrobial/antifungal agents. Antibacterial activities were measured employing ditch plate method against G(+) Staphylococcus aureus, Streptococus faecalis, and G(-) Escherichia coli, Enterobacter aerogenes, and the fungus, Aspergillus niger. All the cotton xanthate-metal-antimicrobial agent chelates exhibited activities whereas the cotton xanthate-metal chelates themselves were inactive. Considering the extensive washing procedures and results from control experiments, possibility of the involvement of physical adsorption for the binding of drugs could be excluded.

• Journal of the Korean Society of Tobacco Science
• /
• v.4 no.2
• /
• pp.63-66
• /
• 1982

Coumarin was pyrolyzed at $500^{\circ}C$ in a stream of nitrogen. The pyrolyzates of coumarin were adsorbed on the activated charcoal and then eluded by carbon disulfide. The eluted pyrolyzates were identified using a gas chromatography/mass spectrometry. Benzene, toluene, phenylacetylene, styrene, benzofuran and naphthalene were detected from the pyrolyzates of coumarin on the basis of their mass spectra. The pyrolytic mechanism of coumarin was also discussed.

• Bulletin of the Korean Chemical Society
• /
• v.26 no.5
• /
• pp.719-728
• /
• 2005

A novel 2-amino-4-(8-quinolinol-5-yl)-1- (p-tolyl)-pyrrole-3-cabonitrile (2) was obtained by the reaction of 2-[2-bromo-1-(8-hydroxyquinolin-5-yl)-ethylidene]-malononitrile (1) with p-toluidene. The new synthon compound (2) could be annelated to the corresponding pyrrolo[2,3-d]pyrimidines (4, 6, 7, 26-28), triazolo[1,5-c]pyrrolo[3,2-e]pyrimidines (10, 29, 30), pyrrolo[2,3-c]pyrazoles (11-15), pyrrolo[1,2-a]pyrrolo[3,2-e] pyrimidine (17) and imidazo[1,2-c]pyrrolo[3,2-e]pyrimidines (18-25) via the reaction with some reagents such as acetic anhydride, formamide, triethyl orthoformate, hydrazine hydrate, hydroxylamine, ethylenediamine, carbon disulfide and phosphorus oxychloride. Chemical and spectroscopic evidences for the structures of these compounds are presented. The antifungal and antibacterial activity of the newly synthesized comounds were evaluated.

• Journal of the Korean Chemical Society
• /
• v.58 no.5
• /
• pp.450-455
• /
• 2014

In the present study, a series of novel N-(1H-benzo[d]imidazol-2-yl)methyl-5-[(hetero)aryl-1,3,4-oxadiazol-2-yl]methanamine (4a-4j) were efficiently synthesized. Condensation of hydrazide derivative 3 with various carboxylic acid derivatives yielded N-[(1H-benzo[d]imidazol-2-yl)methy](5-substituted-1,3,4-oxadiazol-2-yl)methanamine (4a-4j) and compound 5-{[(1H-benzo[d]imidazol-2-yl)methylamino]methyl}-1,3,4-oxadiazole-2-thiol (4k) was obtained on treating hydrazide 3 with carbon disulfide. All the newly synthesized analogues were characterized by IR, $^1H$ NMR, $^{13}C$ NMR and mass spectral data.

• Journal of Environmental Health Sciences
• /
• v.20 no.3
• /
• pp.31-38
• /
• 1994

Dithiocarbamates containing polar groups which give very water soluble metal complexes were prepared from the reaction of carbon disulfide with diamines. The compounds have been characterized by elemental analysis, molar conductivity, and spectroscopic results. Dithiocarbamate and its complex were soluble in water. N, N-Dimethylammoniumpropylenedithiocarbamate(A) is clearly effective as inhibition of cis-platinum nephrotoxicity in rats. From the result of A rescue after cis-dichlorodiammineplatinum(II) treatment, it is suggested that dithiocarbamate removes platinum(II) coordinated to -SH groups bound to protein of kidney tubule cells by the reaction of platinum(II) with dithiocarbamate injected. A is effective as antidots for acute cadmium poisoning in Bacillus subtills. Growth of Bacillus subtills may be accelerated by A ligand dissociated from cadmium (II)-A complex.

• The Korean Journal of Ceramics
• /
• v.5 no.4
• /
• pp.348-352
• /
• 1999

Barium uranium sulfides, $BaUS_3$ and $BaU_2B_5$, were synthesized in a single phase by the reactin of $(Ba, UO_2)(NO_3)_2$ at Ba/U=1 and 0.5 with carbon disulfide at 1273 K for 6 h. They crystallized in orthorhombic structure with space group, Pnma. The lattice parameters a, b and c are 7.493, 10.38 and 7.238$\AA$ for $BaUS_3$ and 7.525, 8.475 and 11.858$\AA$ for $BaU_2S_5$, respectively. The electrical conductivity of these compunds increased with increasing temperature above 200K, below which however, it was nearly temperature independent. The Hall coefficient suggested that they are n-type semiconductors.