• 한국지하수토양환경학회지:지하수토양환경
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• 제17권6호
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• pp.33-42
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• 2012

This study was performed to find the problems according to interference factors (organic matter, pH, Cr, Mn, Fe, clay, and etc.) when we analyzed the hexavalent chromium [Cr(VI)] in soils using UV/VIS spectrometer (US EPA 7196A), attempted to evaluate the domestic applicability of analytical method (US EPA 7199) using IC-UV/VIS spectrometer as alternative method. The recovery rate of certified reference materials was 75.0% (US EPA 7196A) and 101.4% (US EPA 7199) by the analytical methods. As the results of performing QA/QC about US EPA 7199, method detection limit (MDL) and limit of quantification (LOQ) were 0.062 mg/kg, 0.196 mg/kg, respectively. The LOQ of US EPA 7199 was lower than that of the current soil official testing method in Korea (0.5 mg/kg). Cr(VI) contents in 23 soil samples were compared by the analytical methods of EPA 7196A and 7199. Cr(VI) was detected in 13 of 23 soil samples by EPA 7196A, while EPA 7199 was not detected in any soil samples. The Cr(VI) content in 23 soil samples by EPA 7196A was not clearly correlated with Cr, Fe, Mn and clay content in the soil samples. However, the contents of Cr(VI) and organic matter of the soil samples had the highest coefficient of determination ($R^2$) of 0.80. In order to evaluate the correlation between the recovery rates of Cr(VI) and organic matter contents in the soil samples, the recovery rates of 5 soil samples added Cr(VI) standard solution were analyzed by the analytical methods. According to the results, the higher the organic matter contents in soil samples, the lower the recovery rates of Cr(VI) by US EPA 7196, while in case of US EPA 7199, the recovery rates were stable regardless of the organic matter contents.

• 한국식품과학회지
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• 제22권5호
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• pp.520-525
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• 1990

포화지방산 또는 불포화지방산의 분리방법인 요소부 가법이 지닌 가메탄올 분해(methanolysis)와 농축물 회수의 곤란함 등의 문제를 해결하기 위하여 지방산과 요소의 부가화합물 형성의 반응매질로 유기용매를 사용하고 요소의 습윤제로 물을 사용한 새로운 요소부가법을 제시하였다. 어유를 원료로 제조한 지방산을 헵탄, 헥산, 이소옥탄같은 비극성 유기용매에 용해키시고 요소와 요소의 습윤제인 물을 첨가하여 부가화합물 형성을 유도한 후 요소와 부가화합물을 잘 형성하지 않는 불포화지방산 분획을 회수하여 지방산 조성을 분석한 결과 EPA, DHA 및 이들의 전구물질을 포함한 고도불포화지방산이 80%이상인 것으로 나타났다. 이 고도불포화지방산 농축물내에 EPA와 DHA 함량은 사용하는 유기용매으 종류에 따라서 변화되었는데, 헵탄과 에틸 에테르 등을 사용할 경우에는 EPA의 농축에 효과가 높았다. 이러한 특성을 이용하여 우선 펜탄을 사용하여 DHA를 농축하고 다시 헵탄을 사용하여 EPA의 농축을 시도한 바 어유 지방산으로부터 DHA가 50%인 농축물과 EPA가 53%인 분획을 각각 얻을 수 있었다.

• 한국환경보건학회지
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• 제28권2호
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• pp.109-116
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• 2002

The purpose of this study was to evaluate a new sampling and analytical method for the determination of airborne hexavalent chromium, Cr(Ⅵ), in a field plating operation. The procedures of this new method (Shin & Paik's Method) are as the following: Airborne hexavalent chromium is collected on polyvinyl chloride (PVC) filter according to the National Institute iota Occupational Safety and Health (NIOSH) Method 7600, and the filler sample is placed in a screw-capped vial and soaked with 2% NaOH/3% Na₂CO₃ solution immediately after sampling. The Cr(Ⅵ) sample is analyzed by ion chromatography/visible spectrophotometry (IC/VS) according to the U.S. Environmental Protection Agency (EPA) Method 218.6. The airborne Cr(Ⅵ) concentrations measured by this method were compared with those determined by three reference methods: One (NIOSH/EPA Method) consisted of sampling airborne Cr(Ⅵ) on PVC filters and storing the sample filters in strew-capped vials according to the NIOSH method, and analyzing Cr(Ⅵ) in samples using IC/VS according to the EPA method. The second method (Impinger Method/NaHCO₃) consisted of absorbing airborne Cr(Ⅵ) into 0.02 M NaHCO₃ solution in midget impinger, and analyzing the Cr(Ⅵ) in samples using IC/VS. The third method was the OSHA Method ID-215. Using these four different methods, lour replicates of air samples were collected at an electroplating process and analyzed simultaneously. Two-way ANOVA and paired t-test were used to test difference among values determined by the methods. There was no significant difference and a strong correlation (r²:0.99) between Cr(Ⅵ) concentrations measured by the Shin & Paik's Method and an impinger method (p>0.05). However, Cr(Ⅵ) concentrations determined by Shin & Paik's Method were significant1y different from those by the NIOSH/EPA Method (p<0.05) or the OSHA method (p<0.05). The Cr(Ⅵ) concentrations of Shin & Paik's Method were significantly higher than those of the NIOSH/EPA Method or the OSHA method. This result indicated that the Shin & Paik's Method may prevent Cr(Ⅵ) losses caused by reduction and give more reliable results of airborne Cr(Ⅵ) concentrations in work environments.

• 분석과학
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• 제15권3호
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• pp.196-213
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• 2002

물 시료 중 알킬페놀류, 클로로페놀류 및 비스페놀 A의 동시분석을 기체크로마토그래피/질량분석기-선택이온검색법을 사용하여, US EPA 분석방법, isoBOC 유도체화 분석방법과 TBDMS 유도체화 분석방법을 비교하였다. 시료의 전처리는 유기용매로 추출하고 농축하여 분석한 방법과 XAD-4를 이용한 액체-고체 추출 후 isoBOC 유도체화와 TBDMS 유도체화를 실시하였다. 11종의 페놀류에 대한 회수율 실험은 3차 증류수에 각각 10 ${\mu}g/{\ell}$ (US EPA 방법) 또는 2 ${\mu}g/{\ell}$ (isoBOC 유도체화 분석방법과 TBDMS 유도체화 분석방법)의 농도를 대상으로 측정한 결과 각각 85.1~109.9%와 90.3~126.6%의 결과를 얻었다. 각 분석방법의 비스페놀 A에 대한 분석방법 검출한계는 US EPA 분석방법, isoBOC 유도체화 분석방법과 TBDMS 유도체화 분석방법이 각각 0.732 ${\mu}g/{\ell}$, 0.002 ${\mu}g/{\ell}$와 0.021 ${\mu}g/{\ell}$로 나타났으며, $5{\sim}400ng/{\ell}$의 농도 범위에서 isoBOC 유도체화 분석방법과 TBDMS 유도체화 분석방법 각각 0.9755~0.9981과 0.9908~0.9996의 직선성을 보였다. 폴리에틸렌 공장의 방류수를 대상으로 잔류량을 측정한 결과 일부페놀이 검출한계 이하에서 흔적으로 나타났다.

• KSBB Journal
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• 제14권1호
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• pp.109-113
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• 1999

이산화탄소를 용매로하는 초임계유체 크로마토그래퍼(SFC)방법을 이용하여 어유로부터 EPA및 DHA를 고순도로 분리정제하는 연구를 하였다. 질산은 칼럼을 이용하는 초임계 이산화탄소의 초기 압력조건 변화가 저 지방산의 용해도 및 분리도에 미치는 영향을 조사하였는데 압력이 증가될수록 저지방산의 용해도는 증가되었고, 반면에 EPA와의 분리도는 감소하는 경향을 나타내었다. EPA의 분리정제 효율을 높이기 위해 초임계 이산화탄소에 대한 단계별 밀도구매 방법을 적용하였다. 적용 결과 초기에 저지방산이 먼저 분리되었고, 계속해서 92.1%~97.8%EPA 순도를 갖는 분획들을 얻을 수 있었다. 순도가 높은 3개의 분획의 평균 순도는 95.6%이었고 회수율은 30%에 달하였다.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2002년도 춘계 국제 학술대회
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• pp.40.1-43
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• 2002

The purpose of this study was to evaluate a new sampling and analytical method for the determination of hexavalent chromium, Cr(VI) in mist from field plating operation. The Procedures of this new method (Shin & Paik's Method) are as the following: Airborne hexavalent chromium is collected on polyvinyl chloride (PVC) filter according to the National Institute for Occupational Safety and Health (NIOSH) Method 7600, and the filter sample is placed in a screw-capped vial and soaked with 2％ NaOH/3％ Na₂CO₃ solution immediately after sampling. The Cr(VI) sample is analyzed by ion chromatography/visible spectrophotometry (IC/VS) according to the U.S. Environmental Protection Agency (EPA) Method 218.6. The airborne Cr(VI) concentrations measured by this method were compared with those determined by three reference methods: One (NIOSH/EPA Method) consisted of sampling airborne Cr(VI) on PVC filters and storing the sample filters in screw-capped vials according to the NIOSH method, and analyzing Cr(VI) in samples using IC/VS according to the EPA method. The second method (Impinger Method/NaHCO₃) consisted of absorbing airborne Cr(VI) into 0.02 MN/sub a/Hco₃ solution in midget impinger, and analyzing the Cr(VI) in samples using IC/VS. The third method was the OSHA Method Id-215. Using these four different methods, four replicates of air samples were collected at an electroplating process and analyzed simultaneously. Two-way ANOVA and Paired t-test were used to test difference among values determined by the methods. There was no significant difference and a strong correlation (r/sup 2/=0.99) between Cr(VI) concentrations measured by the shin & Paik's Method and an impinger method (p＞0.05). However, Cr(VI) concentrations determined by Shin & Paik's Method were Significantly different form those by the NIOSH/EPA Method (p＜0.05) or the OSHA method (p＜0.05). The Cr(VI) concentrations of Shin & Paik's Method were Significantly higher than those of the NIOSH/EPA Method or the OSHA method. We concluded that the Shin & Paik's Method could prevent Cr(VI) losses caused by reduction and give more reliable results of airborne Cr(VI) concentrations in work environments.

• 분석과학
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• 제10권6호
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• pp.395-402
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• 1997

시료의 매질에 따른 추출법의 문제점과 사용 가능성을 조사하기 위해 환경처 발행의 폐기물공정시험방법과 EPA 3050법을 비교 연구하였다. 이를 위해 sludge와 개펄 시료에 12종의 무기 priority pollutants(Cd, Cr, Cu, Pb, Ni, Zn, As, Sb, Se, Hg, Be, Tl)를 첨가하여 분석용 시료를 조제하고 AAS, HG-AAS, 그리고 ICP/MS를 사용하여 각 추출방법에 대한 대상 원소의 회수율, 상대표준편차 및 method detection limit를 측정하었다. EPA 3050법에 따라 추출한 경우 회수율이 좋지 않은 As, Sb, Se를 제외한 평균 회수율은 93%였다. 그러나 폐기물공정시험방법의 용출시험방법으로 실험한 경우는 전반적으로 회수율이 32%로 매우 좋지 않을 뿐만 아니라 시료의 매질에 의한 영향을 심각하게 받는 것으로 조사되었다.

• 한국응용과학기술학회지
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• 제14권2호
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• pp.49-55
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• 1997

It was tested the possibility that EPA and DHA could be separated from fish oil fatty acid ethyl ester(FAEE) in the supercritical carbon dioxide rectification method. Experiments were carried out in the 1800mm tall and temperature gradient packed rectification column at the pressure of 100bar and carbon dioxide flow rate of 52.43NL/min. Experimental results showed that this method was useful to separate the FAEE by the relative volatility of the components. The maximum attainable concentration of EPA, DHA and both of them in product were 41%, 43% and 57% respectively in this rectification column using raw fish oil feed.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권6호
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• pp.510-515
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• 2006

The putative EPA synthesis gene cluster was mined from the entire genome sequence of Shewanella oneidensis MR-1. The gene cluster encodes a PKS-like pathway that consists of six open reading frames (ORFs): ORFSO1602 (multi-domain beta-ketoacyl synthase, KS-MAT-4ACPs-KR), ORFSO1600 (acyl transferase, AT), ORFSO1599 (multi-domain beta-ketoacyl synthase, KS-CLF-DH-DH), ORFSO1597 (enoyl reductase, ER), ORFSO1604 (phosphopentetheine transferase, PPT), and ORFSO1603 (transcriptional regulator). In order to prove involvement of the PKS-like machinery in EPA synthesis, a 20.195-kb DNA fragment containing the genes was amplified from S. oneidensis MR-1 by the long-PCR method. Its identity was confirmed by the methods of restriction enzyme site mapping and nested PCR of internal genes orfSO1597 and orfSO1604. The DNA fragment was cloned into Escherichia coli using cosmid vector SuperCos1 to form pCosEPA. Synthesis of EPA was observed in four E. coli clones harboring pCosEPA, of which the maximum yield was 0.689% of the total fatty acids in a clone designated 9704-23. The production yield of EPA in the E. coli clone was affected by cultivation temperature, showing maximum yield at $20^{\circ}C$ and no production at $30^{\circ}C$ or higher. In addition, production yield was inversely proportional to glucose concentration of the cultivation medium. From the above results, it was concluded that the PKS-like modules catalyze the synthesis of EPA. The synthetic process appears to be subject to regulatory mechanisms triggered by various environmental factors. This most likely occurs via the control of gene expression, protein stability, or enzyme activity.

• KIEAE Journal
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• 제2권3호
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• pp.55-62
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• 2002

While cognition about an environment pollution becomes important recently, the intense pollution measures about an indoor air environment is required. In the case of building indoor environment, over 80% of modem people is living in building and these days an interest of building interior materials which becomes a reason for indoor environmental pollution in public house, office, is increasing. An experimental measurement method of this study is as follows. (1) American EPA TO-17, ASTMD5116-97, measurement method in VOCs experiment of Japanese closet industrial association (2) 2.4-DNPH cartridge method in HCHO experiment, based on American EPA TO-11 and measurement method of Japanese closet industrial association (3) standard compound is analyzed by using HPLC after solvent extraction process (4) paint and furniture are selected as measurement objects (5) we also made small chamber to grasp an emission characteristic of HCHO and VOCs and to get an environment-amicable forecast model through it, then we developed the model which can forecast emission rate by chamber experiment.