• The Korean Journal of Pesticide Science
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• v.13 no.3
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• pp.133-147
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• 2009

In order to develop the simultaneous analytical method for pesticide residues which ones in soil are rapidly and inexpensively measured by, many analytical methods for individual pesticide residue and several methods for multi-pesticide residues in agricultural commodities and food were reviewed. Various gas chromatographic conditions and pre-treatment procedures were intensively investigated and modified. And then new optimum procedure was established and its proficiency was validated. The response on detectors of simultaneous determination of 180 pesticides out of pesticides used in Korea was tested. The number of pesticides that their limits of detection (LOD) equal or lower than $0.05\;mg\;kg^{-1}$ were 137 pesticides on ECD, 170 pesticides on NPD and 179 pesticides on ECD/NPD integrated. The retention times of most pesticides ranged appropriately between 10 minutes and 40 minutes in the proposed chromatographic conditions. But about 90 pesticides eluded between 20 minutes and 30 minutes and so they were not resolved enough. In partition with dichloromethane, ethyl acetate/hexane (1:1) and ethyl acetate, number of pesticides whose extraction efficiency ranged from 70% to 120%, were 163, 154 and 147, respectively.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.1
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• pp.65-73
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• 2016

Korea Food and Drug Administration (KFDA) has officially announced 2,4-dinitrophenylhydrazine (DNPH) derivatization - high performance liquid chromatography (HPLC) methods for analysis of formaldehyde. This study was conducted to develop a convenient derivatization method for cosmetics by improving complex pre-treatment procedures included in KFDA method. To simplify pre-treatment procedures of KFDA method, reaction conditions including pH, time and temperature were optimized. This pre-treatment method does not require complicate pre-treatment steps of KFDA method such as pH adjustment of test solution with acetate buffer (pH 5.0), solvent-solvent partitioning with dichloromethane and concentrating procedure with vacuum evaporator. Formaldehyde-dinitrophenylhydrazone (formaldehyde-DNP) product produced by derivatization reaction was separated and quantified with a reversed-phase HPLC, which was slightly modified with KFDA method. The linearity test showed good results with 0.9999 of correlation coefficient ($r^2$) in the range of 2 ~ 40 ppm of standard solutions. In this method, limit of detection (LOD) and limit of quantitation (LOQ) values for formaldehyde were 0.2 ppm and 0.5 ppm, respectively. In addition, recovery test demonstrated that the method was also accurate and reproducible. Therefore, the proposed method can be applicable to rapid analysis of formaldehyde in cosmetics.

• Polymer(Korea)
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• v.34 no.1
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• pp.20-24
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• 2010

In this study, ETFE-g-PSSA membranes with various degrees of grafting (DOG) and thicknesses were prepared by a simultaneous irradiation method. SEM-EDX instrument was applied to measure the relative distribution of sulfur which is corresponding to that of a grafted polymer over the Cross-section of the ETFE-g-PSSA membranes prepared at various irradiation conditions. The results indicate that to obtain the evenly-grafted membranes, a styrene/dichloromethane ratio is needed to be under 60 (v/v%), and a higher DOG is required as the film thickness increases. The effects of DOG and thickness on the ion exchanging capacity (IEC) and water uptake (WU) were investigated by measuring the IEC and WU values of the membranes with various DOG and thicknesses.

• Journal of The Korean Society of Clinical Toxicology
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• v.13 no.2
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• pp.78-86
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• 2015

Purpose: The purpose of this study is to understand what kinds of chemical substances have been used annually and to investigate incidents that occurred due to chemical hazard release and to analyze statistically clinically chemical injury patients who visited one regional emergency medical center in Gumi city with documented references review. Methods: Annual chemical waste emission quantity (Kg/Year) (Cwep) was reproduced using national web site data governed by the Ministry of Environment and 5 years (from 1 .Jan. 2010 to 31. Dec. 2014) of medical records of chemical injury patients who visited our emergency department were reviewed retrospectively. By applying exclusion criteria, 446 patients of 460 patients were selected. Results: Dichloromethane, Toluene, Trichloroethylene, and Xylene were always included within Top 5 of Cweq. Six cases of chemical incidents were reported and in 3 of 6 cases involving Hydrogen fluoride were included during the study period. Male gender and twenties were the most prevalent group. Injury evoking chemicals were Hydrogen fluoride, unknown, complex chemicals (over 2 substances) in sequence. The most frequent site of wounds and injuries was the respiratory tract. Gas among status, intoxication among diagnosis, and discharge among disposition was most numerous in each group. Conclusion: There have been no uniform clinical protocols for chemical wounds and injuries due to various kinds of chemicophysical properties and ignorance of antidotes. Therefore conduct of a multicenter cohort study and experiments for ruling out chemicals according to chemicophysical priority as well as development of antidotes and clinical protocols for chemical injury patients is needed.

• Korean Journal of Plant Resources
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• v.26 no.1
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• pp.44-51
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• 2013

Morinda officinalis (MO) is a oriental medicinal herb which has been used traditionally for the treatment of impotence, anti-inflammatory, menstrual irregularity action and various brain diseases including antidepressant and anti-stress. In order to examine the mechanism of anticonvulsive effect, we treated the methanol extract of MO (100, 200 mg/kg, P.0) to the sleeping time and pentylenetetrazol (PTZ)-induced convulsive mice. The methanol extract of MO prolonged sleep time by pentobarbital. Dose-dependent of methanol extracts of MO were effected the concentration of GABA and GABA-T activity in the brain of PTZ-induced mice. Methanol extracts of MO significantly inhibited the convulsion state as well as the level of lipid peroxidation in the brain. The butanol and dichloromethane fraction of methanol extracts among the others effectively inhibited in vitro lipid peroxidation dose dependently ($5.0{\times}10^{-2}{\sim}20.0{\times}10^{-2}g/ml$).

• Journal of Environmental Science International
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• v.15 no.1
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• pp.85-94
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• 2006

The simultaneous analysis of multi-residual pesticides was developed using a gas chromatography (GC) method. In this study, a simple and reliable methodology was improved to detect 154 kinds of pesticides in sinseng extract sample by using a liquid-liquid extraction procedure, open column chromagraphy and chromatographic analysis by CC electron capture detector (ECD) and GC nitrogen-phosphorus detector (NPD). The 154 kinds of pesticides were classified in 4 groups according to the chemical structure. The extraction of pesticides was experimented with $70\%$ acetone and dichloromethane/petroleum ether in order, and cleaned up via open column chromatography $(3\times30cm)$ packed with florisil $(30g,\;130^{\circ}C,\;12hrs)$. The final extract was concentrated in a rotator evaporator at $40^{\circ}C$ until dryness. Then the residue was redissolved to 2ml with acetone, and analyzed by GC-ECD and GC-NPD. The applied concentration of pesticides was over $1\~10{\mu}g/ml$. The recovery tests were ranged from $70.7\%$ to $115.2\%$ with standard deviations between 0.3 and $5.7\%$ of the standard spiked to the ginseng extract sample (Group $I\~IV$). The limit of detection (LOD) ranged from 0.001 to $0.099{\mu}g/ml$ (Group $I\~IV$). The 9 kinds of pesticides were not detected. The developed method was applied satisfactory to the determination of the 154 kinds of pesticides in the ginseng extract with good reproducibility and accuracy.

• Korean Journal of Environmental Agriculture
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• v.28 no.3
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• pp.266-273
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• 2009

This study was conducted to develop more convenient simultaneous determination method by matrix solid phase dispersion (MSPD) and HPLC for sulfonamides such as sulfamerazine (SMR), sulfamethazine (SMT), sulfamonomethoxine (SMM), sulfadimethoxine (SDM), sulfaquinoxaline (SQX), and tetracyclines including oxytetracycline (OTC), tetracycline (TC) chlortetracycline (CTC) in prok and flatfish. The limits of detection were 0.047 $mg{\cdot}kg^{-1}$ for OTC, TC, SMR, SMT and SMM, and 0.033 $mg{\cdot}kg^{-1}$ for CTC, SDM, and SQX, respectively. So it is sufficiently possible to detect the eight tetracyclines and sulfonamides under their MRLs ($0.1{\sim}0.2mg{\cdot}kg^{-1}$). The average percentage recoveries of sulfonamides and tetracyclines from pig muscle and flatfish spiked standard solution were approximately $80.25{\sim}101.25%$ and $85.77{\sim}121.42%$, respectively. Therefore this method was efficient for simultaneous analysis of eight tetracyclines and sulfonamides.

• KSBB Journal
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• v.11 no.1
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• pp.71-76
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• 1996

Studies were carried out to examine some factors affecting the supercritical carbon dioxide extraction of taxol from the bark of Taxus cuspidata using a continuous packed bed extractor. The factors investigated in this study were pressure, temperature, volume of carbon dioxide, and co-solvent. It was found out that the amount of taxol extracted was not significantly affected by the operating pressure in the absence of a co-solvent although it increased by about 20% at 5500 psig. With $24\ell$ of carbon dioxide the saturated amount of taxol was extracted at 318K and 5500psig. Methanol was found to be the most effective co-solvent in terms of amount of taxol extracted among six different co-solvents used. When methanol was used as a co-solvent the effect of operating pressure became significant; approximately 50% increase in the amount of taxol extracted was observed at 3000 psig as compared to at 2500 or 3500psig. The optimum methanol concentration in supercritical fluid was 13% (w/w)at 308K, 3000psig.

• The Journal of Korean Medicine
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• v.26 no.3 s.63
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• pp.27-42
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• 2005

Objectives : Alzheimer's disease (AD) is a progressive and fatal neurodegenerative disease characterized by amyloid plaques and neurofibrillary tangles. These plaques are associated with degenerating neuronal processes and consist primarily of fibrillary aggregates of beta-amyloid$ protein, generated from amyloid precursor protein (APP). Another amyloidogenic fragment, the carboxyl terminus (CT) of APP, which is composed of 99-105 amino acid residues containing the complete $A{\beta}$ sequence, also appears to be toxic to neurones. Recent evidence suggest that CT105, carboxy terminal 105 amino acids peptide fragment of APP, may be an important factor causing neurotoxicity in AD. Methods : Although a variety of oriental prescriptions including Pinelliae rhizoma have traditionally been utilized for the treatment of AD, their pharmacological effects and action mechanisms have not yet been fully elucidated. In the present study, we investigated effects of the dichloromethane extract of Pinelliae rhizoma (PINR) on neurotoxicity and the formation of reactive oxygen species (ROS) and nitric oxide (NO) in SK-N-SH cells overexpressed with CT105. In addition, we evaluated its radical scavenging activity and effects on acetylcholinesterase (AChE) activity. Furthermore, effects on cognitive deficits induced by scopolamine treatment in rats were evaluated. Results ; We found in this study that PINR significantly inhibited apoptotic neuronal death induced by CT105 overexpression in SK-N-SH cells. Based on morphological examinations by phase-contrast microscopy, PINR reversed apoptotic changes of CT105-expressed cells. It was also found that PINR significantly promoted neurite outgrowth and inhibited formation of ROS nd NO. PINR was shown to scavenge DPPH radicals and noncompetitively inhibit AChE activity. Furthermore, it reduced scopolamine-induced memory impairment in rata, assessed by passive avoidance test. Conclusions : Taken together, these results demonstrate that PINR exhibits neuroprotective, antioxidant, and memory enhancing effects, and therefore may bs beneficial for the treatment of AD.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.2
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• pp.87-96
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• 2017

In this study, 4 gases containing typical chlorinated volatile organic compounds (VOCs) were treated by ultraviolet (UV) irradiation. The typical chlorinated VOCs are dichloromethane (DCM), trichloromethane (TCM), carbon tetrachloride (CTC) and trichloroethylene (TCE). The removal efficiency (RE) and the products of chlorinated VOCs by UV irradiation are investigated. At this time, 2 types of background gas (air and nitrogen) were used to figure out the RE by photooxidation and photolysis. The specification of UV-lamp used in this study was low-pressure mercury lamp emitting wavelength of 185~254 nm. The experimental conditions were set as initial VOC concentration of $180{\pm}10ppm$, empty bed retention time (EBRT) of 53 s, temperature of $23{\pm}2^{\circ}C$ and relative humidity of $65{\pm}5%$. In the photolysis condition with nitrogen ($N_2$) as background gas, the averaged RE of the 4 types of chlorinated VOCs was about 24% higher than that with photooxidation; and the REs of VOCs except CTC were confirmed as >99%. The composition of off-gases after UV photooxidation in air was investigated and several intermediates from DCM, TCM and TCE were detected by GC/MS. Among them, phosgene which is a toxics was detected as an intermediate of TCM. In addition, the concentration of carbon dioxide ($CO_2$) in the off-gases was measured to calculate the mineralization rate (MR). With the photooxidation, TCE showed the highest RE (>99%) while MR was the lowest (17%); and the MR of DCM was the highest (86%). In addition, particulate matters (PM) in the off-gases was also detected and high concentrated $PM_{10}$ ($21,580{\mu}g{\cdot}m^{-3}$) and $PM_{2.5}$ ($6,346{\mu}g{\cdot}m^{-3}$) were detected in TCE off-gas. More than 99% of the chlorinated VOCs could be removed using UV254-185 nm lamp, while it is necessary to conduct further studies on the production and treatment of secondary pollutants.