• Environmental Analysis Health and Toxicology
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• 제20권4호통권51호
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• pp.297-302
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• 2005

The purpose of this study was to provide the standard method for the analysis of organophosphorous pesticides such as chlorpyrifos, diazinon, malathion and parathion in blood. We performed method validation for these pesticides in blood according to EURACHEM (A focus For Analytical Chemistry in Europe) guide. For the analysis of the pesticides, we used solid-phase extraction ,column (Waters Oasis $HLB^{(R)}$. After the extraction, the supernatants were evaporated to dryness under the nitrogen stream. They were analyzed by gas chromatography/mass spectrometry (GC/MS) after reconstituting with ethanol. Terbufos was used as an internal standard. To validate this method, we performed verification procedures with the following parameters: selectivity, linearity of calibration, accuracy, precision, limit of detection and quantification. Validation data according to Eurachem guide were adequate for our purpose for the analysis of chlorpyrifos, diazinon, malathion and parathion in blood.

• 한국지반환경공학회 논문집
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• 제18권2호
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• pp.53-58
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• 2017

본 연구에서는 ABAQUS(2014)를 이용한 다공질 매체의 혼합유한요소해석에서 요소 간의 분리를 모사할 수 있는 방법을 제안한다. ABAQUS에서는 변위과 간극수압(u-p모델)의 자유도를 갖는 혼합유한요소의 분리를 standard(implicit) 버전 상에서 cohesive element와 함께 해석을 제안하지만, 요소 간의 이탈, 강체운동, 접촉 등과 같은 분리현상에 대해서는 경계조건 문제로 수치 해석상 한계가 있다. ABAQUS-explicit 해석에서는 경계조건 문제에 대해 자유롭지만 지금까지의 혼합요소 간의 분리를 제공하고 있지 않다. 그러므로, 본 연구에서는 ABAQUS-explicit 상에서 u-p 모델에 대한 분리를 모사할 수 있는 새로운 접근방법이 제안된다. VUMAT 서브루틴을 통하여 구성모델이 적용되고, 간극수압 변화에 따른 요소의 분리 조건을 판단한다. 그리고 VDISP 서브루틴을 통하여 요소의 분리를 발생시킨다. 이렇게 제안된 알고리즘은 간단한 2차원 다공질 매체 예제를 통하여 구현된다.

• 한국환경생태학회지
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• 제16권2호
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• pp.188-194
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• 2002

우리 나라의 도시생태계 평가제도는 도시계획법에 의해 시행되는 제도와 환경관련떱에 의해 시행된는 제도로 구분된다. 도시계획법에 의한 평가제도는 개발행위허가기준과 도시계획 환경성검토가 있으며, 환경관련법에 의해 시행되는 제도는 환경영향평가와 사전환경성검토가 있다. 도시생태계 평가제도는 그 동안 개발지향적인 토지이용정책으로 인해 체계적인 발달이 이루어지지 않았으며, 평가기법도 입목본수도 및 녹지자연도 등을 제외하고는 객관적인 평가기법이 개발되지 알았다. 또한 평가 결과 보전가치가 높은 지역에 대한 보전대책 및 계획과정과 사후에 대한 평가가 부족하다는 문제점을 가지고 있다 우리 나라의 도시생태계 평가제도가 활성화되기 위해서는 다음과 같은 개선방안 마련이 필요하다. (1) 비오톱지도와 같은 객관적인 도시생태계 평가기법 개발, (2) 평가결과 보전가치가 높은 지역에 대한 보전지구 지정 및 훼손에 대한 보상 방안 마련, (3) 도시개발계획과 생태계 보전계획 수립의 병행 및 사후평가 시행

• Environmental Analysis Health and Toxicology
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• 제29권
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• pp.18.1-18.9
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• 2014

Objectives The purpose of this study was to determine a separation method for each arsenic metabolite in urine by using a high performance liquid chromatography (HPLC)-inductively coupled plasma-mass spectrometer (ICP-MS). Methods Separation of the arsenic metabolites was conducted in urine by using a polymeric anion-exchange (Hamilton PRP X-100, $4.6mm{\times}150mm$, $5{\mu}m$) column on Agilent Technologies 1260 Infinity LC system coupled to Agilent Technologies 7700 series ICP/MS equipment using argon as the plasma gas. Results All five important arsenic metabolites in urine were separated within 16 minutes in the order of arsenobetaine, arsenite, dimethylarsinate, monomethylarsonate and arsenate with detection limits ranging from 0.15 to $0.27{\mu}g/L$ ($40{\mu}L$ injection). We used G-EQUAS No. 52, the German external quality assessment scheme and standard reference material 2669, National Institute of Standard and Technology, to validate our analyses. Conclusions The method for separation of arsenic metabolites in urine was established by using HPLC-ICP-MS. This method contributes to the evaluation of arsenic exposure, health effect assessment and other bio-monitoring studies for arsenic exposure in South Korea.

• 한국환경복원기술학회지
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• 제23권6호
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• pp.57-73
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• 2020

A study was conducted to present the criteria for evaluating the revegetation method of the slope of the expressway. The results of comparative analysis between 2019-2020 field survey and existing research data (2015-2016) are as follows. Soil is a very important factor at the beginning of revegetation work. However, after the plant has settled, the importance of the soil composition diminishes. Among the plants used, the number of plants sown at the beginning gradually decreases. And it changes as it competes with invading plants. Among the plants used for sowing, it was found to affect the vegetation composition in the order of exotic grass > native herb and wildflower > native tree. Plant coverage is continuously evaluated as an important factor regardless of the time. The vegetation structure on the slope will change continuously over time. New items need to be evaluated in situations where a lot of time has elapsed since the application of revegetation work. It is desirable to use the current evaluation standard only to perform the evaluation within 1 to 2 years. In the long run, it is necessary to establish a new evaluation standard that adjusts the weights of each item.

• Fisheries and Aquatic Sciences
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• 제25권5호
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• pp.264-275
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• 2022

A non-destructive environmental DNA protocol for the genetic analysis of sea cucumber (Apostichopus japonicus) resources DNA was established. Among the several commercial DNA extraction kits, the DNeasy^® Plant Mini Kit was selected as the best choice to obtain the high-quality genomic DNAs from the mucous sea cucumber. As the temperature and incubation time increased, the amount of extracted environmental DNA was also large, but it was judged that the increased amount did not affect as much as 2-3 times. Therefore, these conditions were not considered to be the main factors to consider in actual environmental DNA extraction. However, the amount of seawater relative to the size of the sample was judged as a major consideration, and a sufficient amount of environmental DNA for analysis was secured when stored within 1 min while stirring the volume of seawater corresponding to the total sea cucumber weight (g). In securing the environmental DNA of sea cucumbers, the mortality rate of sea cucumbers in all experiments was 0, and it was judged that the effects of sea cucumbers were not significant through this treatment. Through the results of this study, sea cucumber DNA research, which has been conducted in a destructive method, can be conducted non-destructively through environmental DNA analysis. Through this study, we have secured a standard protocol that can successfully extract the sea cucumber DNA through environmental DNA. It is not only excellent in terms of time and cost of traditional DNA analysis method currently used, but it is completely non-destructive in the ecosystem of the survey area. It is believed that the system can be transformed in a way that does not affect it. However, it is thought that various standard protocols should be established considering the characteristics of each type.

• 한국환경과학회지
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• 제18권12호
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• pp.1369-1381
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• 2009

The simultaneous determination of residual pesticides was developed using a gas chromatography. In this study, a simple and reliable methodology was improved to detect 175 kinds of residual pesticides by a liquid-liquid extraction procedure, followed by chromatographic analysis by gas chromatography. The 175 kinds of residual pesticides was classified into 4 groups according to the chemical structure, column type, resolution and sensitivity. The soybean sample selected for recovery experiment was not detected any pesticides. The recovery rates were ranged from 70.6% to 119.7% in most pesticides. The relative standard deviation (RSD 0.3~5.6%) was lower than 5.6% in all cases. The limits of detection (LOD) was lower than the maximum residue levels established by Korean legislations. The method has been successfully applied to the analysis of approximately 130 real samples.

• 한국환경보건학회지
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• 제46권6호
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• pp.646-654
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• 2020

Objectives: Users of parks or children's play facilities have pointed to pets' bowel movements as the most serious problem when using them. In prior studies, a very low detection rate of parasites (eggs) in sand flooring materials has been found. Even though feces have been identified, no parasites (eggs) have been detected. Method: A standard solution of nitrate nitrogen was used to verify the reliability of a new nitrogen analysis method. The linearity, precision, and accuracy of the nitrate nitrogen analysis method were verified. Using this method, the pollution distribution of the sand flooring material and the degree of pollution at each point were investigated. Results: As a result of the verification of the nitrogen analysis method, the linearity was found to be good at r2=0.999 when distilled water is mixed in a standard substance solution. The standard substance additive solution r2=0.968 was found to be good. Precision represented 0.01 to 0.06% RSD for peak height. The recovery rate was 92.4 to 104.0 percent, indicating high accuracy. According to the same method of analysis, the flooring material sand at a general amusement facility with the largest number of concealed spaces was nitrate nitrogen 6.1 times higher than at the entrance of the playground. Also, in a comparison between clean sand and sandy flooring, the average nitrogen concentration of the sand flooring material was 24.4-167 times higher than pure sand. Conclusions: As such, no parasites (eggs) were detected at all points under investigation, but the sand flooring was exposed to animal fecal contamination. Therefore, the management of nitrogenous components should allow accurate identification of animal fecal contamination so that the timing of sand replacement can be managed hygienically and safely.

• 분석과학
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• 제8권4호
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• pp.787-792
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• 1995

A method for determination of ammonia-N in environmental water by air-segmented flow injection analysis using the colour reaction of phenol and sodium hypochlorite with ammonia was described in this paper. When the reaction temperature is $70^{\circ}C$ and the reaction residence time is 5 minutes, a sample frequency of $60-90h^{-1}$ can be achieved. The detection limit and relative deviation are $0.05mg.ml^{-1}$ and 4%, respectively. The recovery of this method is 96 - 110%, and the determination results of the method are greatly agreement with standard colorimetric method.

• 한국환경과학회지
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• 제13권10호
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• pp.903-909
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• 2004

A new method based on solid phase microextraction(SPME), coupled with GC/FID, has been developed for the determination of PCE and TCE in water samples. The experimental parameters affecting the SPME process (i.e, kinds of fibers, extraction time, desorption time, extraction temperature, volume ratio of sample to headspace, salt addition, and magnetic stirring) were optimized. The coefficients of determination ($R^2$) for PCE and TCE were 0.9951 and 0.9831, respectively when analytes concentration ranges from 10 to 300$\mu$g/L. The relative standard deviations were 3.4 and $2.1\%$ for concentration of 10$\mu$g/L(n=5), respectively. The detection limits of PCE and TCE were 0.5 and l.3$\mu$g/L, respectively.