• Bulletin of the Korean Chemical Society
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• v.16 no.1
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• pp.17-21
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• 1995

A new series of polyarylate copolyesters were prepared by melt polycondensation of 1,4-diacetoxy-2,5-(α-phenylisopropyl)benzene with mixture of terephthalic acid and isophthalic acid in varying ratio. And their general properties such as the glass transition temperature, crystalline melting temperature, crystallinity and solubility were studied. The intrinsic viscosity values of the present polymers measured in a mixed solvent of phenol/p-chlorophenol/1,1,2,2-tetrachloroethane ranged from 0.45 to 0.66 depending on the composition and molecular weight. The copolyesters containing greater than 20 mole % of isophthalic acid were found to be amorphous, whereas the homopolymer derived from terephthalic acid was semicrystalline with a melting point of 414℃. The glass transition temperatures of the polymers ranged from 165 to 180℃ depending on the composition. The copolyesters containing 50 mole % and greater of isophthalic acid moiety were soluble at room temperature in such common solvents as tetrahydrofuran, chloroform and N,N-dimethylformamide.

• Journal of the Korean Chemical Society
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• v.37 no.5
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• pp.503-512
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• 1993

The purpose of this study was to investigate the retention behavior of phenols and to predict their retention in RPLC. The retention data of twenty-five phenols were measured on a $\mu-{Bondapak}\;C_{18}$ and a polymeric $C_{18}$ columns with methanol-water and acetonitrile-water as a mobile phase. From the observation of enthalpy-entropy compensation phenomenon, the following conclusions are drawn with regard to the retention mechanism: 1) the retention mechanism of nitrophenols in different from that of metheyl-and chlorophenols in both mobile phase; 2) in methanol-water mobile phase, the retention mechanism of methyl-and chlorophenols is consistent in the range of methanol-water composition; 3) on the other hand, in the case of acetonitrile-water mobile phase, the retention mechanism depends on the volume fraction of acetonitrile. It means that the retention mechanism can not be explained only by a simple interaction. Based on retention data as compared with two columns, it may be said that the hydrophobic interaction of phenols with polymeric $C_{18}$ column was greater than that with monomeric $C_{18}$ column. The equations for predicting the retention of phenols were derived by using hydrophobic substituent constant $(\pi)$ and the sum of Hammett's constant $(\sigma)$ and Taft's steric constant $(E_s)$.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.1
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• pp.67-74
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• 2005

Toxicity tests were performed to evaluate the feasibility of application with prediction models to 10 mixture chemicals (chloroneb, butylbenzylphthalate, pendimethaline, di-n-butylphthalate, di-iso-butylphthalate, diazinon, isofenphos, 2-chlorophenol, 2,4,6-trichlorophenol and p-octylphenol) detected in effluents from wastewater treatment plants (WWTPs). Ten chemicals were selected in the basis of their toxicities to Daphnia magna and the concentrations in effluents measured by GC/MS. Three models including concentration addition (CA), independent action (IA) and effect summation (ES) were employed for the comparison of the predicted and the observed mortality of D. magna exposed to 10 mixture chemicals for 48 hours. With a comparative study it was ineffective to predict the mortality through the CA and the ES prediction model, while the IA prediction model showed a high correlation($r^2\;=\;0.85$). Moreover, the ES model over-estimated the toxicity observed by bioassay experiments about five-fold. Consequently, IA model is a reasonable tool to predict the mixture toxicity of the discharging water from WWTPs.

• Analytical Science and Technology
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• v.17 no.5
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• pp.393-400
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• 2004

Nitrosation of phenol (POH) was studied by adding hydrochloric acid and sodium nitrite to phenol solution with reaction temperature and time change. The optimum condition of nitrosation was found from the effects of hydrochloric acid and sodium nitrite concentration, reaction temperature, and reaction time changes on the production of nitrosophenol (POHNO). As a result, it was found that the optimum conditions were $5.0{\times}10^{-4}{\sim}2.0{\times}10^{-3}M$ range of $NO{_2}^-$ concentration, more than 0.10 M of HCl concentration, temperature of $80^{\circ}C$, and 3 hrs. of reaction time. In this condition, 10 U.S. E.P.A. classified priority environmental pollutant, phenols, were nitrosated. Nitrosated phenols were: POH, 2-Chlorophenol (2ClPOH), 2,4-diChlorophenol (2ClPOH), 2,4-dimethylphenol (24diMPOH), and 4-Chloro -3-methylphenol (4Cl3MPOH), and a small part of 2-nitrophenol (2NPOH). The ${\lambda}_{max}$ values of nitrosated phenols in acidic solution were around 300 nm, and those in basic solution were around 400 nm. Molar absorptivities (${\varepsilon}$) at the 400 nm of the nitrosated phenols in the basic solution were 1.5~2.0 times larger than those at 300 nm in acidic solution. It was also found by Capillary-HPLC chromatograms of the nitrosated phenol solutions that the production of the nitrosophenols were interfered by the excess concentration of nitrite (more than $3.0{\times}10^{-3}M$).

• Journal of Korean Society of Environmental Engineers
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• v.30 no.7
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• pp.735-742
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• 2008

In order to evaluate the levels and distribution patterns, the concentrations of PAHs and chlorophenols were investigated in sludge samples discharged from 6 WWTPs located along Nak-dong river and 7 STPs in Busan, Korea. Levels of 16 PAHs and 19 chlorophenols in sludge samples ranged from 1.28 to 44.9 mg/kg dry wt. and from 213 to 3,850 $\mu$g/kg dry wt., respectively. Levels of PAHs in sludge samples except I5 and S4 were detected lower than those of previous studies. The distribution patterns of PAHs and chlorophenols varied with industrial wastewater sludge samples because industrial wastewater sludge had different industrial input sources. However, the distribution patterns of PAHs and chlorophenols in sewage sludge were pretty similar. Phenanthrene, fluoranthene and pyrene were dominant and the fractions of these 3 PAHs relative to 16 PAHs in sewage sludge ranged from 30.8 to 50.7%. 2-chlorophenol is dominated in most sewage sludge samples and the fraction ranged from 36.0 to 66.8%.

• Korean journal of applied entomology
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• v.4
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• pp.47-50
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• 1965

Many of the chlorophenol derivatives are widely used as insecticides, herbicides and plant growth regulators. The function and use of these chemicals would be different according to the number of chlorine and their chemical structures. It was reported in this article that 1) Bis(trichlorophenoxy) ethane was synthesized with 2 mol-trichlorophenol and 1 moi-dibromoethane in 2 moi-Sodium hydroxide alcohol solution, and 3) the insecticidal activity of Bis(trichlorophenoxy) ethane was compared with Phenkapton, Tedion V-18, BHC, and DDT, on Citrus red mite, Bombix mori (Silk worm), and Daikon leaf beetle(Phaedon brassicae) 3) The toxicity of Bis(2, 4, 5-trichlorophenoxy) ethane and Bis(2, 4, 5-trichlorophenoxy) ethane was studied on mice. The following results were obtained. 1) Yield of Bis(2, 4, 5-trichlorophenoxy) ethane, $50.06\%$, m.p. $157-159^{\circ}C$, and yield of Bis(2,4, 6-trichlorophenoxy) ethane, $32.60\%$, m.p. $162-163^{\circ}C$. 2) Insecticidal activity of Bis(2, 4, 5-trichlorophenoxy) ethane to Citrus red mite is stronger than that of Tedion V-18, and weaker than that of Phenkapton. 3) Insecticidal activity of Bis(2, 4, 5-trichlorophenoxy) ethane to Bombix mori is weaker than those of BHC and DDT. 4) Insecticidal activity of Bis(2. 4, 5-trichlorophenoxy) ethane to Daikon leaf beetle proved to be ineffective. 5) Five rams of Bis(2, 4, 5-trichlorophenoxy) ethane and Bis(2, 4, 6-trichlorophenoxy) ethane pet kg of body weight respectively were given to mice orally, and none of the mouse was killed by it after a period of 72 hours. Therefore it seems that there is almost no toxicity.

• Journal of Life Science
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• v.24 no.1
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• pp.54-60
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• 2014

Aromatic hydrocarbons are toxic environmental pollutants that are detrimental to the ecosystem and human health. Among them, chlorotoluene and nitrotoluene are toxic to hydrobios and irritate the skin, eyes, and respiratory organs of humans. We herein report the development of recombinant microbial biosensors for cheap and rapid monitoring of chlorotoluene and nitrotoluene compounds. Plasmids were constructed by inserting the xylR regulatory gene for BTEX (benzene, toluene, ethylbenzene, and xylene) degradation into upstream of Po' (the DmpR activator promoter Po with the deletion of its own upstream activating sequences) or Pu (the cognate promoter of XylR)::lacZ (the ${\beta}$-galactosidase gene) and transformed into Escherichia coli $DH5{\alpha}$. In the presence of inducers, the biosensor cells immobilized in agarose developed a red color in 1-2 h due to the hydrolysis of chlorophenol red ${\beta}$-D-galactopyranoside (CPRG), a substrate of ${\beta}$-galactosidase that was expressed by the inducers. Among BTEX, high responses were specifically observed with o-, m-, p-chlorotoluene ($0.1{\mu}M-100 mM$) and o-, m-, p-nitrotoluene (0.1 mM-100 mM). Po' demonstrated higher responses than those with Pu. The biosensors immobilized in agarose showed good stability after 21 days' storage at $4^{\circ}C$, and responses in untreated wastewater spiked with chlorotoluene and nitrotoluene, suggesting they can be used to detect compounds in wastewater.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.6
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• pp.731-737
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• 1992

The specific attributes of aroma quality of canned tuna meat were investigated before and during refrigerated storage. Fresh, cooked tuna, beefy and meaty flavor notes of canned tuna meat were changed to card-boardy(1 week storage), oxidized fat-like(2 weeks storage), fatty acid-like and heavy oxidized fat-like(3 weeks storage), and then moldy and painty(4 weeks storage) flavor notes during storage in refrigerator at $4^{\circ}C.$ More than 126 peaks of volatile compounds collected from canned tuna meat were separated on Carbowax 20M capillary column of gas chromatographic analysis. Of the peaks, 54 compounds were identified by mass spectral data, matching $I_E$ values, and sniffing the effluent of each peak from GC detector. The contents of many low molecular weight compounds eluted with early retention times were decreased, whereas some other new compounds eluted with longer retention time were formed during storage. The compounds increased up to 3 weeks of storage and then decreased at extended storage time(4 weeks) were 1-penten-3-ol, 3-penten-2-ol, heptanal, limonene, 1-pentanol, octanal, 1-hexanol, nonanal, 2-octanone, 2-nonanone, 1-heptanol, benzaldehytde and some methyl substituted benzenes. p-Thiocresol, 2-chlorophenol, and 2-heptylthiophene were formed after 4 weeks of storage, but not detected in fresh canned tuna. Therefore, these compounds could be used as indicators for the quality changes during refrigerated storage.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.9
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• pp.900-904
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• 2010

Polyvinyl chloride (PVC) hoses, polyethylene hose and silicone hose for tap water were tested with respect to migration of phenolic compounds to water. The highest concentrations (0.36~1.97 mg/L) of total phenolic compounds were observed in the test water from PVC hoses. Increasing residual Cl concentration from 0 to 0.5 mg/L or increasing water temperature from 4 to $25^{\circ}C$ increased 3~3.2 times and 100~104 times for migrated total phenolic compounds concentrations, in respectively. A major migrating phenolic compounds from PVC hoses were bisphenol-a (BPA) and it was observed that the concentration of migrating phenolic compounds in the order: DEHP > 2-chlorophenol > 2,4,6-trichlorophenol > 2,4-dichlorophenol from PVC hoses.

• KSBB Journal
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• v.11 no.6
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• pp.681-688
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• 1996

In the removal of phenolic precipitates formed by horseradish peroxidase (HRP) and $H_2O_2$ from waste water, the effects of the concentrations of phenolic compounds and $H_2O_2$ on the removal efficiency of various phenols were studied. More than 90% of various phenolic compounds were removed from the aqueous solutions (pH 5-7) by HRP and H2O2. The removal efficiency of phenolic compounds by HRP was reduced to a great extent when the initial concentration of $H_2O_2$ was over 10mM. Furthermore, no phenolic compounds were removed when 50mM of $H_2O_2$ was used. The HRP's turnover number, which indicates the number of phenolic molecules removed per one molecule of HRP, was the largest as 18047 for p-ethoxyphenol while it was the smallest as 1244 for m-chlorophenol when the initial concentrations of phenolic compounds and H2O2 were the same at 1mM. HRP which was separated from the aqueous solution containing phenol and $H_2O_2$ after 24hr of reaction revealed structural changes and diminished activity. The Soret absorbance near 404nm of this HRP sample was decreased to 48% of that of fresh HRP. The values of kcat and kcat/Km of this HRP sample for the oxidation of guaiacol were also reduced to 41% and 51% of those of fresh HRP, respectively. The removals of nonphenolic aromatic compounds such as benzene, ethylbenzene, and toluene (BET) by HRP and $H_2O_2$ were enhanced when phenols were coexisting in the aqueous solutions of BET.