• 한국식품위생안전성학회지
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• 제4권3호
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• pp.171-176
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• 1989

영남지방 곡류에 오염되어 있는 Aflatoxin B1을 측정하기 위해 식속하고 정확한 Enzyme-Linked Immunosorbent Assay(ELISA) 법을 응용하였다. 생산된 Antibody 는 aflatoxin B2와 강한 corss reaction을 보였고, 정량적으로 표준곡선을 보인 aflatoxin B1 범위는 1-100ppb이었으며, methanol-PBS-dimethylformamide로 spike시킨 쌀 추출물이 ELISA 반응에 약간의 간섭반응을 보였다. ELISA법에 의한 쌀 65종, 보리 116종의 aflatoxin 분석결과는 다음과 같다. 즉, 쌀시료 65개 중 3개의 시료가 positive 반응을 보였으며, 그중 R-18이 $7.5\;\mu\textrm{g}/kg$, R-30이 $3.6\;\mu\textrm{g}/kg$, R-59가 $3.3\;\mu\textrm{g}/kg$ 순으로 aflatoxin B1 함량을 나타내었고 시료의 4.6%가 aflatoxin B1에 오염되었음을 보였다. 보리 116종 중 겉보리에서 4개의 시료가 positive 반응을 나타내었으며, 그 중 겉보리 UB-37이 $9.6\;\mu\textrm{g}/kg$의 함량으로 가장 높은 함량을 나타내었고, 그의 UB-35, UB-54순이었으며 전체 시료의 3.4%가 aflatoxin B1에 오염되었음을 보였다.

• 공업화학
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• 제28권5호
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• pp.597-600
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• 2017

4,4'-비피리딘과 크롬(VI) 산화물을 반응시켜 $(C_{10}H_8N_2H)_2Cr_2O_7$을 합성하였다. 적외선분광광도법(FT-IR)과 원소분석으로 구조를 확인하였다. 여러 가지 용매 하에서 $(C_{10}H_8N_2H)_2Cr_2O_7$을 이용하여 벤질알코올의 산화반응을 측정한 결과, 용매의 유전상수 값이 증가함에 따라 반응수율이 증가했다. 그 순서는 DMF (N,N'-디메틸포름아미드) > 아세톤 > 클로로포름 > 시클로헥센이었다. $H_2SO_4$ 촉매를 이용한 DMF 용매 하에서, $(C_{10}-H_8N_2H)_2Cr_2O_7$은 벤질알코올(H)과 그의 유도체들($p-OCH_3$, $m-CH_3$, $m-OCH_3$, m-Cl, $m-NO_2$)을 효과적으로 산화시켰다. 전자받개 그룹들은 반응속도가 감소한 반면에 전자주개 치환체들은 반응속도를 증가시켰고, Hammett 반응상수(${\rho}$) 값은 -0.70 (308 K)이었다. 본 실험에서 알코올의 산화반응 과정은 속도결정단계에서 수소화 전이가 일어났다.

• Elastomers and Composites
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• 제42권4호
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• pp.238-248
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• 2007

일련의 방향족 polyhydroxyamides(PHA)를 저온 용액 중축합으로 합성하였다. 이들 중합체들은 FT-IR, $^1H-NMR$, DSC, TGA 그리고 PCFC를 이용하여 특성들을 조사하였다. PHA 중합체들의 고유점성도는 DMAc 용매 하에 $35^{\circ}C$에서 $0.5{\sim}1.1dL/g$의 값을 나타내었다. PHA 3을 제외한 중합체들은 N,N-dimethylacetamide(DMAc), N-methyl-2-pyrrolidone(NMP), N,N-dimethylformamide(DMF) 등과 같은 극성 유기 용매에 용해되었지만, 열적 고리화 반응에 의해 전환된 polybenzoxazoles(PBOs)는 용해되지 않았다. PBO 3을 제외한 PBO 중합체들에서는 DSC에서 $200{\sim}246^{\circ}C$의 유리전이온도($T_g$)를 보였고, TGA에서의 최대분해온도는 질소 분위기 하에서 $597{\sim}697^{\circ}C$의 범위를 보였다. PBO 중합체들은 $51{\sim}64%$의 높은 차 수득률을 보였다. PCFC에서 PBOs의 heat release(HR) capacity는 $8{\sim}65J/gK$의 값을 보였고, total heat release(total HR)의 값은 $2.4{\sim}4.7kJ/g$을 보였다.

• Macromolecular Research
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• 제17권10호
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• pp.739-745
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• 2009

N,N'-(bicyclo[2,2,2]oct-7-ene-tetracarboxylic)-bis-L-amino acids 3a-g were synthesized by the condensation reaction of bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride 1 with two equimolars of Lalanine 2a, L-valine 2b, L-leucine 2c, L-isoleucine 2d, L-phenyl alanine 2e, L-2-aminobutyric acid 2f and L-histidine 2g in an acetic acid solution. Seven new poly(amide-imide)s PAIs 5a-g were synthesized through the direct polycondensation reaction of seven chiral N,N'-(bicyclo[2,2,2]oct-7-ene-tetracarboxylic)-bis-L-amino acids 3a-g with bis(3-amino phenyl) phenyl phosphine oxide 4 by two different methods: direct polycondensation in a medium consisting of N-methyl-2-pyrrolidone (NMP)/triphenyl phosphite (TPP)/calcium chloride ($CaCl_2$/pyridine (py), and direct polycondensation in a tosyl chloride (TsCl)/pyridine (py)/N,N-dimethylformamide (DMF) system. The polymerization reaction produced a series of flame-retardant and thermally stable poly(amide-imide)s 5a-g with high yield. The resulted polymers were fully characterized by FTIR, $^1H$ NMR spectroscopy, elemental analyses, inherent viscosity, specific rotation and solubility tests. Data obtained by thermal analysis (TGA and DTG) revealed that the good thermal stability of these polymers. These polymers can be potentially utilized in flame retardant thermoplastic materials.

• 한국산업보건학회지
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• 제18권4호
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• pp.303-309
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• 2008

The reduction of risk within the workplace has long been focus of attention both through industry initiatives and legislation. Exposure matrices according to industries and processes treated DMF (N,N-Dimethylformamide) were constructed based on KOSHA (Korean Occupational Safety and Health Agency)'s 2005 exposure database which were gathered from Korean agencies of workplace hazards evaluation for business place. These exposure matrices were assessed by danger value (DV) that was calculated from combination of hazard rating, duration of use rating, and risk probability rating of exposure to chemical hazardous agents in accordance with Hallmark Risk Assessment Tool. The results of risk assessment is divided four kinds of control bands which were related with control measures. The applicability of risk assessment using exposure matrices was performed by field study and survey for high matrices group. This study found that more attentions should be paid to two industries, manufacture of sewn wearing apparel and manufacture of textiles, among 19 industries, and to 3 processes, coating, processing & mixing, and lab, among 80 processes because those were regarded as having the highest risk.

• 대한화학회지
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• 제25권4호
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• pp.283-290
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• 1981

N,N-디메틸포름아미드용매내 반응온도 50∼$90^{\circ}C$범위에서 과량의 슈크로오스와 라우르산, 미리스트산, 팔미트산, 스테아르산 그리고 올레산등 5종의 지방산 메틸에스테르와의 에스테르 교환반응에서 반응속도를 측정하여 반응속도정수, 활성화파라미터등을 구하여 고찰하였다. 이 반응은 본 실험범위내에서 유사 1차반응으로 진행하고 반응의 순서는 주로 메틸에스테르의 지방산기의 구조변화에 의존하면 라우르산메틸, 미리스트산메틸, 팔미트산메틸 올레산메틸 그리고 스테아르산 메틸의 순으로 반응되기 힘들어지는 엔탈피조절반응이라 생각된다. 한편 이들 각각의 활성화에너지는 9.3, 9.9, 10.3, 10.9 그리고 11.1 kcal/mole이 얻어졌다.

• 분석과학
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• 제27권6호
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• pp.339-346
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• 2014

근로자 건강진단 실무지침 상의 필수 검사항목 항목 중, N-메틸아세트아미드의 소변 표준시료를 제조하여 그 신뢰도를 확인하고자 하였다. DB-624 컬럼을 사용한 GC/MSD 분석 방법에 의해 기존 분석 컬럼보다 우수한 분리능과 선택성으로 N-메틸아세트아미드를 분석하였다. -60, -20, 5, $25^{\circ}C$에서 5-50 mg/L의 농도 범위의 소변 중 N-메틸아세트아미드의 안정성을 6개월 보관 시점까지 검토한 결과 모든 보관 조건에서 안정하였으며, 각 시료에 대한 균질성 검사 결과도 양호하였다. 이상의 결과로부터 유리형 NMAC를 첨가하는 방법으로 제조한 소변 중 NMAC 표준시료가 분석정도관리용으로 실용화하기에 적합한 균질성과 장기간 보관 시의 안정성을 모두 만족시킴을 확인하였고, 2008년부터 분석정도관리 표준시료로 활용하였다.

• 멤브레인
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• 제17권4호
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• pp.359-368
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• 2007

본 연구에서는 불소계 고분자인 PVdF (poly(vinylidene fluoride))에 HFP (hexafluoropropylene)가 결합된 공중합체인 PVdF-HFP로 충전용 이차전지의 분리막으로 쓰이는 다공성 막을 상전이 방법으로 제조하였다. 용매인 DMF (N,N-dimethylformamide)에 PVdF-HFP를 단일상으로 녹인 후 깨끗한 유리판에 캐스팅하여 막을 얻었다. 기공은 증류수로 채워진 응고조에서 용매-빈용매 교환으로 형성되어진다. 얻어진 분리막에서 가장 높은 공극률은 60%로 얻어졌다. 시차주사현미경(scanning electron microscopy, SEM)을 이용하여 분리막의 단면 관찰을 통해 다공성을 확인하였고 UTM (universal testing machine)을 이용하여 측정된 분리막의 인장강도는 PVdF-HFP 30 wt%에서 최대 6.57 MPa의 값을 나타내었다.

• Journal of Korean Society for Atmospheric Environment
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• 제15권E호
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• pp.29-38
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• 1999

This study identified emission sources and emissions of air pollutants such as volatile organic compounds (VOCs), solvents, and acid gases produced from chemical plants. We collected air samples from various processes, reactors and facilities using VOC detectors and workers' experience. We identified chemical structures and emission concentrations of air pollutants. We analyzed total emissions of air pollutants emitted from the chemical plants. Also, we developed some emission reduction technologies based on chemical types and emission situations of the identified air pollutants. For reduction of air emissions of acid gases, we employed a method improving solubility of pollutants by reducing scrubber operation temperature, increasing surface area for effective contact of gas and liquid, and modifying or changing chemicals used in the acid scrubbers. In order to reduce air emissions of both amines and acid gases, which have had different emission sources each other but treated by one scrubber, we first could separate gas components. And then different control techniques based on components of pollutants were applied to the emission sources. That is, we first applied condensation and then acid scrubbing method using H2SO4 solution for amine treatment. However, we only used an acid scrubbing method using H2O and NaOH solution for acid gas treatment. In order to reduce air emissions of solvents such as dimethylformamide and toluene, we applied condensation and activated carbon adsorption. In order to reduce air emissions of mixture gases containing acid gases and slovents, which could not be separated in the processes, we employed a combination of various air pollution control devices. That is, the mixture gases were passed into the first condenser, the acid scrubber, the second condenser, and the activated carbon adsorption tower in sequence. In addition, for improvement of condensation efficiency of VOCs, we changed the type of the condensers attached in the reactors as a control device modification. Finally, we could successfully reduce air emissions of pollutants produced from various chenmical processes or facilities by use of proper control methods according to the types and specific emission situations of pollutants.

• IMMUNE NETWORK
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• 제6권2호
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• pp.76-85
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• 2006

Background: Chemotaxis is one of the cardinal functions of leukocytes, which enables them to be recruited efficiently to the right place at the right time. Analyzing chemotactic activities is important not only for the study on leukocyte migration but also for many other applications including development of new drugs interfering with the chemotactic process. However, there are many technical limitations in the conventional in vitro chemotaxis assays. Here we applied a new optical assay to investigate chemotactic activities induced in differentiated HL-60 cells. Methods: HL-60 cells were stimulated with 0.8% dimethylformamide (DMF) for 4 days. The cells were analyzed for morphology, flow cytometry as well as chemotactic activities by a time-lapse videomicroscopic assay using a chemotactic microchamber bearing a fibronectin-coated cover slip and an etched silicon chip. Results: Videomicroscopic observation of the real cellular motions in a stable concentration gradient of chemokines demonstrated that HL-60 cells showed chemotaxis to inflammatory chemokines (CCL3, CCL5 and CXCL8) and also a homeostatic chemokine (CXCL12) after DFM-induced differentiation to granulocytic cells. The cells moved randomly at a speed of $6.99{\pm}1.24{\mu}m/min$ (n=100) in the absence of chemokine. Chemokine stimulation induced directional migration of differentiated HL-60 cells, while they still wandered very much and significantly increased the moving speeds. Conclusion: The locomotive patterns of DMF-stimulated HL-60 cells can be analyzed in detail throughout the course of chemotaxis by the use of a time-lapse videomicroscopic assay. DMF-stimulated HL-60 cells may provide a convenient in vitro model for chemotactic studies of neutrophils.