• Fisheries and Aquatic Sciences
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• 제17권1호
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• pp.67-73
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• 2014

The oil in mackerel muscle was extracted using an environment friendly solvent, supercritical carbon dioxide (SC-$CO_2$) at a semibatch flow extraction process and an n-hexane. The SC-$CO_2$ was maintained at a temperature of $45^{\circ}C$ under pressures ranging from 15 to 25 MPa. The flow rate of $CO_2$ (27 g/min) was constant during the entire 2 h extraction period. The fatty acid composition of the oil was analyzed using gas chromatography (GC). Significant concentrations of eicosapentaenoic acid (EPA) acid and docosahexaenoic acid (DHA) acid were present in the SC-$CO_2$ extracted oil. The oil extracted using SC-$CO_2$ exhibited increased stability compared with n-haxane extracted oil. Particles of mackerel oil together with the biodegradable polymer, polyethylene glycol (PEG) were formed using a gas saturated solution process (PGSS) with SC-$CO_2$ in a thermostatted stirred vessel. Different temperatures ($45-55^{\circ}C$), pressures (15-25 MPa) and a nozzle size $400{\mu}m$ were used for PGSS with a 1 h reaction time. The stability of mackerel oil in the particles did not changed significantly.

• 한국환경보건학회지
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• 제39권6호
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• pp.483-491
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• 2013

Objectives: Electronic cigarettes are battery powered devices that convert a nicotine-containing liquid into an inhalable vapor. The device aerosolizes nicotine so that it is readily entrained into the respiratory tract, from where it enters the bloodstream. Information on the safety of E-cigarettes is required. Methods: Seventeen articles on studies analyzing toxic substances in the liquid and gas phases of electronic cigarettes were reviewed. Results: Tobacco-specific nitrosamines, bis(2-ethylhexyl) phthalate, formaldehyde and acetaldehyde, known to be carcinogenic agents in humans or animals, were detected in the liquid and gas phases. In addition, diethyl phthalate, acetone, ethanol, cresol, xylene, propylene, styrene, triethylene glycol, tetraethylene glycol, pentaethylene glycol cis-3-hexen-1-ol, methyl cinnamate and undecane were identified in the liquid and gas phases of E-cigarettes. Propylene glycol, glycerin, 1-methoxy-2-propanol, 1-hydroxy-2- propanone, acetic acid, 1-menthone, 2,3-butanediol, menthol, carvone, maple lactone, benzyl alcohol, 2-methyl-2-pentanoic acid, ethyl mantel, ethyl cinnamate, myosamine, benzoic acid, 2,3-bipyridine, cotinine, hexadecanoic acid, and 1'1-oxybis-2-propanol were detected in the vapors of E-cigarettes. Conclusion: The hazardous compounds identified in the liquid and gas phases of E-cigarettes should be controlled for the lowest concentrations in the raw materials and production procedures.

• 분석과학
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• 제15권5호
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• pp.445-450
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• 2002

해수에 함유되어 있는 요오드화합물의 총량을 휘발성 유기물로 유도체화 후 측정하는 방법을 확립하였다. 이 방법은 요오드 음이온은 요오드로 산화시킨 후 2,6-dimethylphenol과 반응하여 4-iodo-2,6-dimethylphenol로 전환시켜 ethylether로 1단계 추출 후 gas chromatography-mass spectrometry (selected ion monitoring)로 측정하는 것으로 구성되어 있다. Iodate는 ascorbic acid 와 acetic acid로 요오드 음이온으로 환원시킨 후 요오드 음이온 측정법과 동일하게 수행하였다. 이 방법은 검출한계가 해수에서 0.1 ng/ml이었으며 검량선은 0.9997의 좋은 상관계수값을 보였다. 이 방법은 또한 재현성이 우수하고 간단하여 해수에 인체의 필수원소인 요오드를 낮은 농도까지 분석하는데 유용하게 사용될 수 있다고 사료된다.

• 한국표면공학회지
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• 제55권6호
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• pp.433-440
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• 2022

Environmental pollution caused by power plant exhaust gas is highlighted and eco-friendly regulations are being strengthened. However, due to the abundant reserves and low prices of coal, still the most used for power generation in the world. Therefore, flexible operation of coal-fired power plants to reduce emissions has become an inevitable option. However, lowering the output increases the possibility of acid dew point corrosion as the exhaust gas temperature decreases. The dew point corrosion occurs when condensable gases such as SO₃, HCl, NO₂ and H₂O cools below the saturation temperature. SO₃ is already well known to cause severe low- temperature corrosion in coal-fired power plants. Therefore, this study aims to prevent damage that may occur during operation by analyzing the dew point and corrosion resistance with exhaust gas temperature and sulfuric acid concentration of the power plant economizer tube.

• 산업기술연구
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• 제19권
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• pp.409-413
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• 1999

Chemical oxidation of humic acid by ozonation process was investigated in the batch reactor. Aldehydes and ketone were identified as PFBOA derivatives in ozonated humic acid solutions using gas chromatography with PDECD. The formaldehyde was as a main by-product of ozonation. The characteristics of the formaldehyde production were discussed with respect to concentration at different experimental conditions.

• 한국산업보건학회지
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• 제9권1호
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• pp.23-40
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• 1999

The analysis of thiodiglycolic acid in urine has been used as an index of biological exposure to vinyl chloride. Unfortunately thiodiglycolic acid has a strong hydrophilic character, because it has two carboxylic groups, so that it can only be extracted with organic solvent with a great difficulty. Underivatized thiodiglycolic acid tends to tail because of non-specific interaction with the inert support. Therefore, esterification is the obvious first choice for derivatization of thiodiglycolic acid, particularly for gas chromatography. In this study, the focus of interest is to compare two method of esterifications (methylation and silylation). Methylation is to make the methyl ester of thiodiglycolic acid by reaction with diazomethane. Silylation is to make the trimethylsilyl ester of thiodiglycolic acid by reaction with N-trimethylsily-ldiethylamine. The results and conclusions are as the following: 1. The detection limit (sensitivity) of methylated thiodiglycolic acid was $5.00{\mu}g/m{\ell}$ and silylated thiodiglycolic acid was $3.07{\mu}g/m{\ell}$ by gas chromatography with flame ionization detector. 2. The optimal liquid-liquid extraction of thiodiglycolic acid was as following: To each of the tubes, $15m{\ell}$ of urine, concentrated sulfuric acid (pH 1 - 2) and 5 gsodium sulfate were added. The samples was extracted three times with $5m{\ell}$ ethylacetate each time. 3. The methylated thiodiglycolic acid was more stable than silylated thiodiglycolic acid in extractional solvent which contained humidity. 4. The precision (pooled coefficient of variation for 4 days) of the analysis was 0.07324 in methylated thiodiglycolic acid with external standard calibration, and 0.07033 in methylated thiodiglycolic acid with internal standard calibration. 5. The precision (pooled coefficient of variation for 4 days) of the analysis was 0.10914 in silylated thiodiglycolic acid with external standard calibration, and 0.13602 in silylated thiodiglycolic acid with internal standard calibration. From the above results, the analysis of methylated thiodiglycolic acid was more sensitive (limit of detection) than silylated thiodiglycolic acid by gas chromatography. However, the methylated thiodiglycolic acid was stable in the humidity and was separated sharply on chromatogram. Also, analysis of methylated thiodiglycolic acid was more precise (pooled coefficient of variation for 4 days) than silylated thiodiglycolic acid. In conclusion, it is established that the analysis of methylated thiodiglycolic acid is appropriate for biological monitoring of exposure to vinyl chloride.

• 한국식품과학회지
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• 제6권2호
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• pp.86-90
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• 1974

Amorpha-fruticosa 종자(種子)의 지방(脂肪)을 ether 및 methanol로 추출(抽出)하여 정제(精製)한 다음, methyl eestorification 시켜 Gas chromatography로 지방산(脂肪酸)을 분석(分析)하고 몇 가지 화학적(化學的) 성질(性質)을 시험(試驗)하여 다음과 같은 결과(結果)를 얻었다. 1. Amorpha-fruticosa 종자(種子)의 일반성분(一般成分)은 수분(水分) 17.65%에서 조단백(粗蛋白) 21.02%, 조지방(粗脂肪) 12.04%, 회분(灰分) 5.74%로서 일반두료식물(一般豆料植物)과 비교하면 대두(大豆), 검정콩을 제외(除外)한 다른 종류(種類)에 비하여 비교적 우수한 성분함량을 나타내고 있다. 2. 각종(各種) 유기용매(有機溶媒)에 의한 본시료(本試料)의 지방추출율(脂肪抽出率)은 ether가 80.25%, methanol 80.00%로서 대등한 수치(數値)이며, benzene 77.34%, hexane 69.96%의 순위(順位)로 나타났다. 3. Ether에 의하여 추출(抽出)된 지방산(脂肪酸)의 chemical constants는 검화가 178.67, 산가 3.11, 요오드가 54.27로 측정(測定)되었다. 4. Ether에 의하여 추출(抽出)된 지방산(脂肪酸)을 gas chromatography에 의하여 분석(分析)한 결과(結果) 모두 8종(種)이 검색(檢索)되었으며 이 중(中) linoleic acid (78.73wt%), palmitic acid (5.68wt%), oleic acid (5.85wt%), stearic acid (4.84wt%), linolenic acid (3.40wt%)의 순(順)으로 함량(含量)이 높으며 arachidic acid (1.06wt%), lauric acid (0.26wt%), myristic acid (0.20wt%) 등은 소량(小量)으로 나타났고 capric acid는 측정(測定)되지 않았다. 5. Methanol로 추출(抽出)한 지방산(脂肪酸)은 ether에서와 같이 8종(種)이 검색(檢索)되었으며 함량(含量)은 linoleic acid (77.86wt%), palmitic acid (7.77wt%), oleic acid (5.74wt%), stearic acid (4.97wt%), linolenic acid (3.56wt%)의 순(順)으로 비교적 함량(含量)이 많고 arachiaic acid (0.01wt%), lauric acid (0.01wt%), myristic acid (0.01wt%) 등은 함량(含量)이 낮으며 역시 capric acid는 ether에서와 같이 측정(測定)되지 않았다.

• 한국축산식품학회지
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• 제32권1호
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• pp.112-117
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• 2012

본 연구는 아질산염과 아스코르브산을 직접 첨가하는 방법을 개선, 대체하기 위하여 아질산염과 아스코르브산 유래 가스를 이용하여 유화형 소시지를 제조하고, 발색 및 물리적 특성에 미치는 영향을 분석하고자 수행하였다. 대조구는 아질산염 150 ppm, 아스코르브산 450 ppm을 직접 첨가하여 제조하였으며, 실험구는 동일량의 아질산염과 아스코르브산을 반응시켜 생성된 가스를 포집하여 유화물 제조에 사용하였다. 대조구 및 실험구에서 원료육 보다 높은 pH를 보였으나, 저장기간 중 pH의 범위가 6.22-6.34로 큰 변화는 보이지 않았다. 육색의 경우 원료육에 비해 높아진 명도(lightness, CIE $L^*$)와 적색도(redness, $a^*$)를 보였으며, 저장기간 중 실험구가 대조구에 비해 낮은 적색도, 높은 황색도(yellowness, $b^*$)를 나타내었다(p<0.05). 그러나 명도의 경우 실험구와 대조구간 차이를 보이진 않았다. 물리적 특성 변화로 가열 및 저장감량에서 실험구와 대조구간 차이가 관찰되었으나(p<0.05), 보수력 및 전단력에서는 유의적인 차이를 보이지 않았고, 저장기간 중 실험구와 대조구 모두에서 저장감량이 증가됨을 확인하였다(p<0.05). 이러한 결과를 종합해 볼 때 아질산염과 아스코르브산 유래 가스의 처리가 유화물의 발색 및 물리적 특성에 있어 아질산염과 아스코르브산을 직접 처리한 경우와 유사한 효과를 나타내며, 이는 아질산염과 아스코르브산 유래 가스가 아질산염과 아스코르브산을 직접 첨가하는 방법을 개선, 대체할 수 있을 것으로 판단된다.

• 한국자원식물학회지
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• 제11권2호
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• pp.202-209
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• 1998

Through total fatty acid analysis by the Gas chromatography, 17 different fatty acids were identified from the sap extracted from bark of Korean Rhus(Anacardiaceae), six species. Linoleic acid(C18 :2) and oleic acid(C18 : 1) were identified as major fatty acids for the species investigated, but except in R. chinensis.In the fatty acid composition for the species, one or two specific-fatty acid was detected, and its could be utilized as a useful taxonomic character.The result of cluster analysis by the 22 reliable characters in the fatty acid composition suggested first group was R.trichocarpa and R. succedanea, the second group, R.verniciflua, R.ambgua and R. sylvestris, but R.chinensis was a greatly independent species. The possible chemotaxonomic application of the fatty acid composition of bark in the genus Rhus was discussed.

• 한국습지학회지
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• 제25권4호
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• pp.291-296
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• 2023

철강산업의 산 회수설비에서 발생하는 염화수소 가스를 처리하기 위하여 마이크로버블을 발생할 수 있는 습식스크러빙 장치(DIWS)가 도입되었다. 산 회수 설비에서 발생하는 염소가스는 수소 가스와 결합하여 염화수소 가스의 농도를 50% 정도 증가시켰다. DIWS장치에 염소 제거를 위한 Na₂S₂O₃를 투입한 이후의 유입수 염화수소 가스 농도는 13.1 ~13.4 ppm, 유출수는 1.5~1.7 ppm이었고, 제거율은 87.5~88.8%로 안정되게 유지하였다. DIWS는 대기배출기준을 안정적으로 만족함에 따라 현장 적용에 적용할 수 있는 공정으로 판단된다.