• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.16-19
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• 2006

Humin is the insoluble fraction of humic materials and play an important roles in the irreversible sorption of hydrophobic organic contaminants onto soil particles. However, there have been limited knowledge about the sorption and chemical properties of humin due to the difficulties in its separation from the inorganic matrix(mainly clays and oxides). In this study, do-ashed humin was isolated from a soil sample after removing free lipid and alkali-soluble humic fractions followed by dissolution of mineral matrix with 2% HF, and characterized by elemental analysis, C-13 NMR spectroscopic method. Sorption behavior of 1-naphthol with humin was also investigated from aqueous solution. C-13 NMR spectra indicate that humin molecules are mainly made up of aliphatic carbon including carbohydrate, methylene chain etc.. Sorption intensity for 1-naphthol was increased as organic carbon content of humin increased and log Koc values for the 1-naphthol sorption were determined to be ${\sim}3.12$

• Journal of the Korean Wood Science and Technology
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• 제29권3호
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• pp.83-91
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• 2001

This paper examines the structural characteristics of fern lignins (deer fern (Blechnum spicant), sword fern (Polystichum munitum) and maidenhair fern (Adiantum pedatum)) by chemical degradation methods of thioacidolysis and nitrobenzene oxidation as well as 13C NMR. Phloroglucinol-HCI staining indicates that the lignins are specifically accumulated at the sclerenchyma cells beneath the epidermis and vascular bundles. The fern lignins consist of only guaiacyl units. Remarkably, the frequency of the -O-4 linkages is extremely low in fern lignins (only 9 to 11 %). Furthermore, the presence of lignin is ambiguous in maidenhair fern, due to very rare amount of -O-4 linkage. Biphenyl (5-5) and 1,2 bis arylpropane (-1) are main condensed dimeric substructures in fern lignins over 70%. In addition, 13C NMR analysis strongly evidenced the integration of phenolics or their derivatives into the fern lignins.

• Bulletin of the Korean Chemical Society
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• 제13권2호
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• pp.135-139
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• 1992

The mono(aryl)cyanoplatinum(II) complex $[Pt(CN)(C_6H_3{CH_2NMe_2}_2-26)]$, reacts with the dihalogens to yield the mono(aryl)cyanoplatinum complexes $[PtX_2(CN)(C_6H_3{CH_2NMe_2}_2-26)]$, (X = Cl, Br, I). The structural configuration of the two halogen atoms for a square planar platinum complex was studied by 1H-NMR spectroscopy and led to a mixture of trans and cis orientation. The trans orientation was found to be more stable in energy (1.33 kcal/mol) than the cis orientation by means of Extended H ckel calculations. On the base of a combination of the analysis of $^1H-NMR$, $^{13}C-NMR spectra and computational calculations it is assumed that the intermediate consists of an initial attack in the linear transition state, leading to the $S_{N}2$ type mechanism.

• 한국응용과학기술학회지
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• 제36권1호
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• pp.84-89
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• 2019

대장균 효소 ${\beta}$-gal를 이용하여 합성된 BzO-gal의 분자구조를 NMR ($^1H$-와 $^{13}C$-)과 고성능 mass spectrometry를 이용하여 분석하였다. BzO-gal은 $^1H$ NMR에서 14개의 proton으로부터 12개의 피크를 나타내었다. 방향족 고리에서 오는 5개의 proton 피크와 벤질기의 $CH_2$에서 오는 2개의 proton 피크는 벤질알코올이 존재함을 나타낸다. 지방족 사슬 영역인 ${\delta}_H$ 4.32 ~ 3.46 ppm에서 나타나는 7개의 proton 피크로부터 단당류가 도입되었음을 확인할 수 있었다. $^{13}C$ NMR 스팩트럼에서 나타난 11개의 carbon 피크도 또한 벤질알코올에 단당이 도입되었음을 나타낸다. BzO-gal의 분자량을 확인하기 위하여 mass spectrometry 로 분석한 결과 m/z가 293.0994인 BzO-gal의 sodium adduct ion($[M+Na]^+$)을 확인할 수 있었다. 이러한 결과를 바탕으로 세포독성이 감소된 첨가물 개발을 기대하고 있으며, 추가적인 후속연구를 진행할 예정이다.

• Bulletin of the Korean Chemical Society
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• 제7권6호
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• pp.413-421
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• 1986

Hydrocarbon solution of $Cp_2Zr(CH_3)Cl$ react rapidly with $Na_2Fe(CO)_4$ (1/2 equiv.) to yield $[Cp_2Zr(CH_3)]_2Fe(CO)_4$ and NaCl. The more soluble metal-metal bonded complex $[Cp_2ZrC_8H_{17}]_2Fe(CO)_2$ has also been prepared through the reaction of $Cp_2Zr(C_8H_{17})BF_4$ and $Na_2Fe(CO)_4 (1/2 equiv.). The complexes were characterized by IR, $^1H$ NMR, ^{13}C$ NMR, and elemental analysis. The infrared spectrum of $[Cp_2ZrR]_2Fe(CO)_4$ shows four bands, which is indicative of a cis-structure. The $^{13}C$ NMR spectrum provides evidence for the cis-structure.

• 한국자기공명학회논문지
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• 제17권2호
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• pp.81-85
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• 2013

Various fluorine-containing materials are used in electronic devices like LCD display panels and Li-ion batteries. The structural conformation of fluorine in fluorinated materials is an important contributing factor that influences the chemical and physical properties. The conformation can be changed by heat and stress during manufacture or use. Understanding the conformational changes is critical for understanding the performance and durability of electronic devices. Solid-state NMR spectroscopy could be widely used for the analysis of various fluorine-containing materials for electronic devices. However, conventional CPMAS probes cannot be used for in-situ analysis of fluorine-containing electronic devices like LCD panels and Li-ion batteries. In this paper, we show the design, construction, and optimization of a $^{19}F-^{13}C$ double-resonance solid-state NMR probe for a 400MHz wide-bore magnet with a flat square coil for in-situ analysis of fluorine-containing electronic devices without observing fluorine background signals. This custom-built probe does not show any fluorine background signals, and can have higher efficiency for lossy samples.

• 한국축산식품학회지
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• 제41권2호
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• pp.312-323
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• 2021

The purpose of this study was to use 1H nuclear magnetic resonance (1H NMR) to quantify taste-active and bioactive compounds in chicken breasts and thighs from Korean native chicken (KNC) [newly developed KNCs (KNC-A, -C, and -D) and commercial KNC-H] and white-semi broiler (WSB) used in Samgye. Further, each breed was differentiated using multivariate analyses, including a machine learning algorithm designed to use metabolic information from each type of chicken obtained using 1H-13C heteronuclear single quantum coherence (2D NMR). Breast meat from KNC-D chickens were superior to those of conventional KNC-H and WSB chickens in terms of both taste-active and bioactive compounds. In the multivariate analysis, meat portions (breast and thigh) and chicken breeds (KNCs and WSB) could be clearly distinguished based on the outcomes of the principal component analysis and partial least square-discriminant analysis (R2=0.945; Q2=0.901). Based on this, we determined the receiver operating characteristic (ROC) curve for each of these components. AUC analysis identified 10 features which could be consistently applied to distinguish between all KNCs and WSB chickens in both breast (0.988) and thigh (1.000) meat without error. Here, both 1H NMR and 2D NMR could successfully quantify various target metabolites which could be used to distinguish between different chicken breeds based on their metabolic profile.

• 한국자기공명학회논문지
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• 제5권2호
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• pp.91-98
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• 2001

The $^1$H and $^{13}$ C NMR spectra of chivosazole F from Sorangium cellulosum were completely assigned by a combination of ID and 2D NMR techniques. The configurations of double bonds were confirmed from the ROESY spectra. The stereochemistry at asymmetric carboncenters was partially assigned on the basis of the results of NOE analysis.

• 생약학회지
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• 제9권1호
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• pp.1-9
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• 1978

The principle of Fourier Transform Nuclear Magnetic Resonance and its usefulness in the fields of pharmacy and biological sciences are described. 1. The $^1H\;and\;^{13}C$ NMR spectra of triostin A and its mixture with purine derivatives were taken. From the analysis of the spectra it has established that triostin A, which exists in two symmetric conformers in chloroform solution, forms complexes only with purine derivatives by the participation of one of the conformers. 2. Also, the $^{13}C$ NMR spectra of "intact" substances in the field of pharmacognosy were taken. From the spectra it was suggested that the method is very useful for natural product research in cooperation with the chemical method.

• 폴리머
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• 제26권4호
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• pp.452-461
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• 2002

본 연구에서는 폴리아미드 6 (PA 6)을 70~$160^{\circ}C$에서 장시간 사용하였을 때 산화방지제의 사용유무 및 농도에 따른 열 안정성을 조사하였다. 70~$160^{\circ}C$의 온도범위내의 열 산화반응 시 모든 시료는 100시간 내에 황변 현상이 일어났다. 기계적 물성, 황변 지수, 점도측정으로 가장 적정한 산화방지제의 농도를 조사하였다. 일, 이차 산화방지제의 조성변화에 의한 산화방지효과는 미미하였다. 황변 현상의 분석은 NMR, IR, 그리고 element analysis (EA)를 사용하였다. $^{13}C$ NMR에 의해 서로 다른 카르보닐기의 존재를 확인하였으며, 산소의 소모량 측정은 EA를 사용하였다. Arrhenius식을 이용하여 산화방지제를 첨가한 시료와 그렇지 않은 시료의 lifetime을 예측하였다.