• The Korean Journal of Pesticide Science
• /
• v.15 no.4
• /
• pp.502-506
• /
• 2011

Most countries have the legislation and regulation for POPs control in food. In here, we studied the quantitative analysis of 24 organochlorine POPs (${\alpha}$-HCH 1, ${\beta}$-HCH 2, ${\gamma}$-HCH 3, ${\delta}$-HCH 4, trans-chlrodane 5, 2,4'-DDE 6, ${\alpha}$-endosulfan 7, cis-chlordane 8, 2,4'-DDD 9, endrin 10, ${\beta}$-endosulfan 11, 2,4'-DDT 12, endosulfan sulfate 13, HCB 14, aldrin 15, trans-nonachlor 16, 4,4'-DDE 17, dieldrin 18, 4,4'-DDD 19, cis-nonachlor 20, 4,4'-DDT 21, heptachlor 22, heptachlor epoxide 23 and mirex 24) with GC-ECD. The retention time of analytes were ranged between 19.18 min and 34.69 min, and their peak intervals were over 0.05 min at least. LOQs were ranged 0.003 ~ 0.033 ng/g, and their recovery rates were showed 60.9 ~ 120.8% on the 0.1 ng/g concentration of 24 organochlorine POPs. All tested 30 sundried salts were collected on Korean retailed market, and any analyte was not found in all the samples on LOQ levels.

• Journal of Conservation Science
• /
• v.36 no.6
• /
• pp.475-482
• /
• 2020

In this study, we synthesized rosin-based epoxy resin and manufactured two components adhesives and epoxy putty using this epoxy resin. This study manufactured main element of adhesives for enabling it to form epoxide group by letting epichlorohydrin react to maleic anhydride modified rosin, and used room temperature curing type triethylenetetramine for hardener. The ratio between main element and hardener of of manufactured adhesives was 100 : 20, and main element and hardener of filling material were manufactured as clay type by mixing them with filler. Manufactured undiluted adhesives and filling material showed very stable result in the adhesive strength (3.06 MPa) and ultraviolet irradiation, showing outstanding result comparing to existing restoration adhesives. And it is considered a material having reversibility as it was dissolved in organic solvents such as acetone and toluene after being hardened, which showed a result that solved part of possible problems caused by restoration. As a result of use and application of manufactured adhesives and filling material for actual wood crafts, they showed excellent results in workability, stability, removability etc., and this study confirmed that the material can be used for and applied to various fields.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.9
• /
• pp.2675-2679
• /
• 2013

Activity-directed isolation of the methylene chloride fraction from the stems of Parthenocissus tricuspidata have led to the identification of two new compounds (1-2): 1-(2',3',5'-trihydroxyphenyl)-2-(4"-hydroxyphenyl)-ethane-1,2-(E)-epoxide (1, tricuspidatin A) and erythro-1-(3',5'-dihydroxyphenyl)-2-(4"-hydroxyphenyl)-ethane-1,2-diol (2, tricuspidatin B), together with four known compounds (3-6): ${\beta}$-sitosterol (3), nonacosan-1-ol (4), 3-(4-hydroxy-3-methoxyphenyl)-2-propenoic acid hexacosyl ester (5) and betulinic acid (6). Their chemical structures were elucidated based on spectroscopic (IR, UV, MS, 1D and 2D NMR) and physicochemical analyses. Compounds 1 and 2 showed strong DNA topoisomerase II inhibitory activity at both concentrations of 20 and $100{\mu}M$. In addition, 3 exhibited strong cytotoxic activity against the HT-29 and HepG2 cancer cell lines, and 6 showed strong cytotoxicity against the HT-29 and MCF-7 ones.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2009.06a
• /
• pp.262-263
• /
• 2009

To add Nanofiller in the epoxy which is used with the solid insulation material of existing and is a research which observes the improvement of the structural quality to produce the Nanocomposite. Montmorillonite uses with Nanofiller, MMT of the content expense (wt%) which is various and mixed an epoxide and produced sample. According to content of the sample result MMT according to respectively content expense to measure SEM photographing which is the possibility of knowing the minute structure of section with sample where is produced and the tensile strength will be able to observe the change of quality. MMT silicate layer uniformly more in the result and within epoxy matrix, being dispersed, will be able to observe.

• Toxicological Research
• /
• v.11 no.1
• /
• pp.23-29
• /
• 1995

Microsomes from human liver sample HL 110 oxidized aflatoxin $B_1$ $(AFB_1)$ to $AFB_1$ exo-8, 9-epoxide which was detected as a glutathione (GSH) conjugate with excess GSH S-transferase and to aflatoxin $Q_1$ ($AFB_1$; 3$\alpha$-hydroxyafiatoxin $B_1$), and testosterone to 6$\beta$-hydroxytestosterone. Anti-P450 3A4 nearly completely inhibited all of the reactions. Some fiavonoids inhibited all of the reactions. While other fiayonolds stimulated 8, 9-epoxidation and inhibited 3$\alpha$-hydroxylation. Gestodene inhibited all of the reactions when gestodene was metabolized by human liver microsomal P450 3A4 prior to adding substrate. But, ges-todene was added in the enzyme mixtures in the presence of $AFB_1$, it could not inhibit 8, 9-epoxidation of $AFB_1$. Nifedipine and troleandomycin inhibited both of the reactions of $AFB_1$ but only 3$\alpha$-hydroxylation was inhibited by the oxidation product of nifedipine. Although, troleandomycin was known as a mechanism-based inhibitor, the chemical did not show any detectable inhibitory effect on 6$\beta$-hydroxylation of testosterone. The results suggest that there are several different substrate-binding sites on P450 3A4.

• Journal of Ginseng Research
• /
• v.35 no.3
• /
• pp.339-343
• /
• 2011

Polycyclic aromatic hydrocarbons (PAHs) are well known environmental carcinogens. PAH metabolites, especially BaP-7,8- dihydrodiol, 9,10 epoxide, initiate carcinogenesis via high specificity binding to DNA to form DNA adducts. The Korean red ginseng (KRG) from Panax ginseng has been suggested to protect against damages due to PAH exposure but the mechanism is unknown. Therefore, we investigated effects of KRG on PAH exposure using toxicokinetic methods and changes of PAH-induced oxidative damage during a 2 week-clinical trial (n=21 healthy young female, $23.71{\pm}2.43$ years). To analyze antioxidative effects of KRG, we measured changes in the levels of urinary malondialdehyde (MDA) before and after KRG treatment. We observed a significant positive association between levels of urinary MDA and 1-hydroxypyrene, a biomarker of PAH exposures (slope=1.47, p=0.03) and confirmed oxidative stress induced by PAH exposures. A reverse significant correlation between KRG treatment and level of urinary MDA was observed (p=0.03). In summary, results of our clinical trial study suggest that KRG plays a significant role in antioxidative as well as toxicokinetic pathways against PAHs exposure.

• Journal of Korean Society for Atmospheric Environment
• /
• v.23 no.4
• /
• pp.457-465
• /
• 2007

This study was performed to estimate the gas-particle partitioning of organochlorine pesticides (OCPs) in atmosphere, the samples were collected by PUF high volume air sampler for two years from June, 2000 to June, 2002. The gas phase fraction of ${\alpha/\gamma}-HCH$, heptachlor epoxide, ${\alpha/\gamma}-chlordane$ and trans-nonachlor was over 90%. But the gas phase fraction of ${\beta}-HCH$, p,p'-DDE, endosulfan sulfate, p,p'-DDD and p,p'-DDT was range of 20% through 80%, which means the gas phase fraction of OCPs components described above is sensitive to temperature. The correlation between the gas phase fraction and molecular weight of each OCPs component was not found in this research. The slope of regression line between gas-particle partitioning coefficient(${\log}K_p$) and subcooled liquid vapor(${\log}{P^o}_L$), gal-particle partitioning coefficient(${\log}K_p$) and octanol-air partitioning coefficient(${\log}K_{oa}$) which show -0.54 and 0.43 was not steep. So the equilibrium state between gas and particle was not reached and in this state the particulate fraction was low.

• Environmental Analysis Health and Toxicology
• /
• v.22 no.2 s.57
• /
• pp.111-118
• /
• 2007

This study was performed to measure gaseous Organochlorine Pesticides (OCPs : heptachlor epoxide, ${\alpha}/{\gamma}-chlordane$, trans-nonachlor, endosulfan, ${\gamma}-HCH$ and p, p'-DDE) concentration using PUF high volume sampler from June, 2000 to June, 2002 in the semi-rural atmosphere. Using monitoring data for two years, we tried to investigate the annual cycles of gaseous OCPs. We considered three functions to describe the annual cycle: Gaussian, Lorentzian and sinusoidal functions. These functions accounted for $54{\sim}91%$ of the variability in concentration for each gaseous OCPs, and the sinusoidal function gave the best fits. It was seen that the gaseous OCPs concentration increased during the warmer weather while decreased during colder weather. The variation of the gaseous OCPs concentration was closely similar to the variations of ambient temperature. The annual cycle of endosulfan was strongly higher than in comparison with other gaseous OCPs, while for ${\gamma}-HCH$, the cycle was weakly high and did not show apparent seasonal variation. The position of the annual maximum exists generally late July to early August. The period that showed levels more than a half maximum was from late June to early September.

• Environmental Analysis Health and Toxicology
• /
• v.22 no.4
• /
• pp.299-304
• /
• 2007

This paper was studied to investigate the equilibrium state between organochlorine pesticides (OCPs) concentration of air and soil, and to know whether soil is a secondary pollution source of OCPs in air or not. The OCPs concentration of air ($C_{air}$) and soil ($C_{soil}$) is not related to molecular weight, vapor pressure ($P_L$) and octanol-air partition coefficient ($K_{oa}$). The slope of the regression line between soil-air partition coefficient ($K_{sa}$) and scavenging coefficient ($C_{soil}/C_{air}$) was 0.2952, which the OCPs concentration between air and soil did not reached to the equilibrium state. The soil/air fugacity quotients ($f_{soil}/f_{air}$) of p, p'-DDT/DDD/DDE and ${\beta}-HCH\;(0.30{\sim}0.67$), which is smaller than 1, means the deposit of OCPs from air to soil. However, $f_{soil}/f_{air}$ of heptachlor, heptachlor epoxide, ${\alpha}/{\gamma}-chlordane$, trans-nonachlor, endosulfan sulfate and ${\alpha}/{\gamma}-HCH\;(1.90{\sim}73.25)$, which is greater than 1, means that soil is secondary pollution source of OCPs in air.

• Journal of Korean Society for Atmospheric Environment
• /
• v.18 no.4
• /
• pp.275-284
• /
• 2002

Atmospheric concentrations of organochlorine pesticides (OCPs) in Seoul, South Korea between July 1999 and May 2000 were determined to investigate concentration distribution in air, relationship between concentrations and meteorological conditions, and apportionment of sources e.g. local sources (air- surface exchange) and long range transport. Endosulfan and $\alpha$-HCH were the highest concentrations in atmosphere with values typcally ranging from 10s to l00s of pg/㎥. These high concentrations may be attributed to their usage, period and chemical property (Koa). All OCPs also showed elevated levels during the summer and were positively correlated with temperature. This would suggest that a seasonal enhancement was due to (re)volatilization from secondary sources and application during the warmer months. The temperature dependence of atmospheric concentrations of OCPs were investigated using plots of the natural logarithm of partial pressure (In P) vs reciprocal mean temperatures (1/T), and environmental phase-transition energies were calculated for each of the pesticides. For OCPs, temperature dependence was statistically significant (at the 99.99% confidence level) and temperature accounted for 35~95% of the variability in concentrations. The relatively higher slopes and phase-transition energies for $\alpha$-, ${\gamma}$-chlordane, endosulfan and endosulfan sulfate suggested that volatilization from local sources influenced their concentrations. The relatively lower those for $\alpha$-, ${\gamma}$-HCH, p, p'-DDE and heptachlor epoxide also suggested that volatilization from local sources and long range transport influenced their concentrations.