• 한국염색가공학회지
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• 제27권4호
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• pp.261-269
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• 2015

Two new D-${\pi}$-A dyes were synthesized by the condensation reaction between active methyl and aromatic aldehyde and its biothiol sensing properties in DMSO/water were investigated by UV-vis spectroscopy. Upon addition of $Hg^{2+}$, the solution of D-${\pi}$-A dyes showed color change and the absorption band shows a formation of a dye-$Hg^{2+}$ coordination complex. These dyes exhibited high selectivity for $Hg^{2+}$ as compared with other cations. The dye-$Hg^{2+}$ could be recovered by adding glutathion(GSH). The absorption intensity of dye-$Hg^{2+}$ increased only by the addition of glutathione(GSH). The competition experiments revealed that no obvious interference was observed by performing the titration with the mixture of glutathione(GSH) and other amino acids. The results indicated that these D-${\pi}$-A dyes were highly selective for glutathione(GSH) detection.

• Bulletin of the Korean Chemical Society
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• 제10권1호
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• pp.75-80
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• 1989

The approximate rates and stoichiometry of the reaction of excess potassium 9-sec-amyl-9-boratabicylco[3.3.1]nonane (K 9-sec-Am-9-BBNH) with selected organic compounds containing representative functional goups under standardized conditions (tetrahydrofuran, $0^{\circ}C)$ were examined in order to explore the reducing characteristics of the reagent for selective reductions. The reagent readily reduces aldehydes, ketones, acid chlorides and epoxides to the corresponding alcohols. However, carboxylic acid, aliphatic nitriles, t-amides, and some sulfur compounds show very little reactivity or no reactivity to this reagent. The most interesting feature of the reagent is that aromatic nitriles are reduced moderately to the corresponding aldehyde stage, wheras aliphatic nitriles are inert. In addition, the reagent shows a high stereoselectivity toward cyclic ketones at $0^{\circ}C$ and - $25^{\circ}C.$ The selectivity exhibited at $0^{\circ}C$ is comparable to that by lithium trisiamylborohydride at that temperature.

• Asian-Australasian Journal of Animal Sciences
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• 제33권1호
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• pp.148-156
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• 2020

Objective: This study aimed to evaluate the effect of dietary integration with extruded linseed (EL) on fatty acid (FA) and aromatic profile of goat cheese after 60 (T₆₀) days of ripening. Methods: Thirty goats were divided in two groups. The control group (CG) was fed with conventional diet, whereas the experimental group (EL+) was fed with conventional diet supplemented with 10% of EL. Milk samples were collected on 30 and 60 days of trial to determinate chemical-nutritional composition and FA profile. At the end of experiment, six cheese-making sessions (3 for each group) were carried out using a pooled milk sample obtained from the 15 goats of each group. At 60 days of ripening, cheeses were analyzed for chemical-nutritional composition, FA and aromatic profile. Results: An increase in the milk production, protein, fat and lactose were evidenced in the EL+ goats. Conversely, a reduction of somatic cells was observed in the EL+ compared with the CG. However, no variation was observed for urea and casein levels content in milk samples, and no changes in protein and lipid content were found for cheeses in the two experimental groups. Dietary supplementation with EL modified the FA profile of milk. There was a decrease in saturated FAs and an increase in polyunsaturated FAs. Chemical composition of T₆₀ cheese did not differ between the two groups but a different FA profile was observed. In T₆₀ cheese obtained from EL+ milk, an increase in short-chain FA and a decrease in medium and long-chain FA were observed. The EL diet led to cheeses with butanoic acid 2 times higher compared to CG cheeses. Moreover, a greater presence of aldehyde compounds and alcohols were observed in the cheeses of experimental group. Conclusion: The present study pointed out that EL supplementation may improve the chemical and physical qualities of goat milk and cheeses.

• 임산에너지
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• 제17권1호
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• pp.56-70
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• 1998

This study was carried out to investigate the structural characteristics of kraft lignin and the wood degrading characteristics, the productivity of ligninolytic enzymes and the enzymatic degradation of kraft lignin by white-rot fungi. To purify kraft lignin, precipitation of kraft pulping black liquors of pitch pine meal was done by titration with lN $H_{2}SO_{4}$ reaching to pH 2, and isolation of the precipitates done by centrifugation. The isolated precipitates from pitch pine were redissloved in lN NaOH, reprecipitated by titration with lN $H_{2}SO_{4}$, washed with deionized water, and kept ofr analysis after freeze drying. Fractionation of the precipitates in solution by successive extraction with $CH_{2}Cl_{2}$ and MeOH, and the fractionates were named SwKL, SwKL I, SwKL II, and SwKL III for pitch pine kraft lignin. The more molecular weights of kraft lignin increased, the less phenolic hydroxyl groups and the more aliphatic hydroxyl groups. Because as the molecular weights increased, the ratio of etherified guaiayl/syringyl(G/S ratio) and the percentage were increased. The spectra obtained by 13C NMR and FTIR assigned by comparing the chemical shifts of various signals with shifts of signals from autherized ones reported. The optimal growth temperature and pH of white-rot fungi in medium were $28^{\circ}C$ and 4.5-5.0, respectively. Especially, in temperature and pH range, and mycelial growth, the best white-rot fungus selected was Phanerochaete chrysosporium for biodegradation. For the degradation pathways, the ligninolytic fungus jcultivated with stationary culture using medium of 1% kraft lignin as a substrate for 3 weeks at $28^{\circ}C$. The weight loss of pitch pine kraft lignin was 15.8%. The degraded products extracted successively methoanol, 90% dioxane and diethyl ether. The ether solubles were analyzed by HPLC. Kraft lignin degradation was initiated in $\beta$-O-4 bonds of lignin by the laccase from Phanerochaete chrysosporium and the degraded compounds were produced from the cleavage of $C\alpha$-$C\beta$ linkages at the side chains by oxidation process. After $C\alpha$-$C\beta$ cleavage, $C\alpha$-Carbon was oxidized and changed into aldehyde and acidic compounds such as syringic acid, syringic aldehyde and vanilline. And the other compound as quinonemethide, coumarin, was analyzed. The structural characteristics of kraft lignin were composed of guaiacyl group substituted functional OHs, methoxyl, and carbonyl at C-3, -4, and -5 and these groups were combinated with $\alpha$ aryl ether, $\beta$ aryl ether and biphenyl. Kraft lignin degradation pathways by Phanerochaete chrysosporium were initially accomplished cleavage of $C\alpha$-$C\beta$ linkages and $C\alpha$ oxidation at the propyl side chains and finally cleavage of aromatic ring and oxidation of OHs.

• 농약과학회지
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• 제4권4호
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• pp.12-18
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• 2000

제초제 quinclorac의 수중 및 토양중 잔류량을 인위적으로 감소시키기 위하여 광분해를 촉진시킬 수 있는 6종의 감광제를 선발하여 수중 및 모래에서의 광분해 시험을 수행하였다. 자연광 조건하에서 증류수중 quinclorac의 분해는 암조건과 비교할 때 차이가 없어 직접적인 광분해는 용이하지 않음을 알 수 있었다. Methanol 용액에서 quinclorac의 광분해율은 40.3%였으나, 감광제 PS-1 (방향족 ketone), PS-3 (quinone), 그리고 PS-6 (반도체 광촉매)가 함유되어 있는 용액 및 현탁액에서 quinclorac의 광분해율은 각각 96.6%, 72.7%, 그리고 95.7%로서 가장 양호한 광분해 촉진효과를 보였다. 한편 모래에서는 감광제 PS-1, PS-3 그리고 PS-6중에서 PS-3가 64.1%로 가장 양호한 광분해 촉진효과를 보였다. Methanol중 quinclorac의 광분해산물로 5종의 화합물이 그리고 감광제 PS-1에서는 3종의 분해산물이 GC-MS로 구명되었고 aldehyde기를 보유한 광분해산물은 sodium 3,5-dinitrosalicylate의 환원반응에 의하여 확인되었다. 토양에 처리된 quinclorac은 30 ppm 이상의 감광제 PS-3 처리로 광분해되어 남아있는 quinclorac 잔류물은 강피를 방제하지 못했다. 이와 같은 결과들은 감광제 PS-1, PS-3, PS-6가 수용액 및 토양중 quinclorac 잔류물을 효과적으로 광분해시킬 수 있음을 시사한다.

• 한국물환경학회지
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• 제21권5호
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• pp.484-489
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• 2005

In order to determine the removal rate of non-biodegradable substances and the change of their structural properties, this study was carried out by an ozone-treatment experiment on leachate collected from the landfill area of D City in Chung chung nam-do and examined the change of the chemical properties of non-biodegradable substances. The main elements of non-biodegradable substances in landfill leachate were benzene, toluene, trichloroethane, trichloroethylene, xylene, etc. and the concentration of toluene was 15.7 mg/L on the average, benzene 7.2 mg/L, trichloroethane 1.1 mg/L, trichloroethylene 0.75 mg/L and xylene 0.5 mg/L. When leachate was treated with ozone for 10 min, 30 min and 60 min, UV absorbance was reduced with the increase of reaction time, and the reduction rate was 38.6% at 60 min. TOC was removed by 13.2% at 60 min. The low reduction rate of TOC may be because TOC reacts indirectly with OH radical produced from reaction with ozone while UV absorbance usually relies on direct reaction between organic matters and ozone molecules. Color was removed by up to 97%, which suggests that ozonation is highly effective in removing coloring elements in leachate. Sixteen kinds of non-biodegradable compounds were found in the leachate and most of them had the characteristic of aromatic hydrocarbon. Among them dibutyl phthalate was identical with a substance included in the list of US EPA, which is classified as a mutagen that may cause the mutation of genes and disorders in chromosomes. In addition, 2,5-Cyclohexadiene-1,4-dione, 1,2-Benzenedicarboxylic acid and butyl octyl ester were found to be similar to substances listed by USEPA. According to the result of analyzing structural changes before and after ozonation using GC-MS, cyclic compounds and aromatic compounds were observed in the original water and aliphatic compounds were newly observed after ozonation. In addition, through ozonation, humic substances of high molecular weight were oxidized and decomposed and produced low-molecular compounds such as aldehyde, ketone and carboxyl acid and highly biodegradable aliphatic carbon, which suggests the bio-degradability of non-biodegradable substances.

• 한국재료학회지
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• 제7권11호
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• pp.957-963
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• 1997

PVC 핏치를 산소분위기에서 안정화시킬 때 발생되는 화학반응 기구를 열중량 분석 및 FT-IR을 이용하여 규명하였다. PVC 핏치를 안정화시킬 \ulcorner 초기에 가속화현상이 이러나서 핏치내에 반응성이 강한 메칠기(-CH/ sub 3/)나 메칠렌기(-CH$_{2}$-)등이 산소와 반응하여 카보닐기(C=O)를 생성하면서 급격한 무게증가 현상이 발생하였다. 이때의 생성물들은 알데히드(aldehyde), 케톤(ketone), 알코올(alcohol)이며, 물 (H$_{2}$O)이 부산물로 발생된다. 이 가속화 현상에 의해 핏치내의 메칠기와 메칠렌기는 안정화 초기단계에서 대부분 산화되어 없어졌다. 안정화시간이 길어짐에 따라 생성된 알데히드나 일차 알코올의 산화가 발생하여 카르복실산(carboxylic acid)을 생성하고, 에테르 결합도 생성되었다. 이때에도 무게증가 현상이 발생하지만, 초기의 급격한 무게증가와는 달리 그 증가속도가 느리고, 시간이 경과함에 따라 증가속도는 더욱 느려졌다. 그리고, 안정화온도가 높고 안정화시간이 긴경우에는,카르복실산들의 탈수반응으로 인한 방향족 무수화물(aromatic anhydride)이 생성되었다. 29$0^{\circ}C$에서 24시간 안정화시킨 경우, 무게감소가 발생했는데, 이것은 카르복실산의 탈카르복실화(decarboxylation)반응에 의해 CO$_{2}$가 발생되었기 때문이다. 그리고, 안정화 온도가 높을수록 안정화에 무게증가의 최대값과 방향족 무수화물이 발생되는 무게증가 값이 작아지고, 안정화 초기단계에서 나타나는 가속화 현상의 구간도 짧아졌다.

• Bulletin of the Korean Chemical Society
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• 제34권12호
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• pp.3755-3761
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• 2013

This study aims to assess the ecological risk of the hazardous air pollutants (HAPs) emitted in the semiconductor manufacturing processes in Korea by using Quantitative Structure Activity Relationship (QSAR, EPA, US, EPI $Suite^{TM}$ 4.1). Owing to the absence of environmental standards of hazardous air pollutants in the semiconductor manufacturing processes in Korea, 18 HAPs in the semiconductor field included in both the US EPA NESHAPs and the hazardous air pollutant list of Ministry of Environment in Korea were selected. As a results 8 chemicals (44.4%) of the selected 18 HAPs were VOCs. Cyanides (cyanides) and ethylene oxides (epoxy resins), and tetrachloro-ethylene (aliphatic compounds, halides) showed long half-lives. Cyanide HAPs especially had the highest half-life with the estimated value of 356.533 days. Nickel compounds (heavy metal compounds) possessed the highest water solubility followed by acetaldehyde (aldehyde compounds), ethylene oxides, and 1,4-dioxanes. The halides, including tetrachloro-ethylenes, carbon tetra-chlorides, benzene (aromatic compounds), and lead (heavy metals), are estimated to take the longest time for biodegradation. Tetrachloroethylene, with the acute toxicity end point of 3.685-7.033 mg/L, was assessed to be the most highly toxic substance among the 18 HAPs. However, considering the absence of the HAPs in the common category of log $K_{ow}{\geq}4$and $BCF{\geq}500$, which indicates the standard of bioconcentration potentials, potentials of the bioconcentration are considered to be low.

• 한국환경과학회지
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• 제17권7호
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• pp.767-774
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• 2008

This study was carried out to evaluate the characteristics of atmospheric concentrations of volatile organic compounds(VOCs) and aldehydes for near a large shipyard. Most of the painting work in marine coating is performed indoor and outdoor. Most of the VOCs are emitted to the atmosphere as the paint is applied and cures. The massive scale of a ship makes it difficult to capture the emissions from outdoor painting. The VOCs are an important health and contributors to photochemical smog. The VOCs and aldehydes samples were collected using adsorbent tube and 2,4-DNPH cartridge, and were determined by an automatic thermal desorption coupled with GC/MS and HPLC-UV analysis, respectively. A total of 16 aromatic VOCs and 12 aldehydes of environmental concern were determined. At indoor coating facilities, the most abundant compound among 16 target VOCs appeared to be m,p-xylene, being followed by o-xylene. But most of the aldehydes were extremely lower concentrations. The atmospheric concentration of VOCs, m,p-xylene concentrations were the highest and the mean value were outdoor workshop 11.323 ppb, residental area 5.134 ppb, and green area 2.137 ppb, respectively. However, the most aldehydes were extremely lower concentrations such as formaldehyde, acetaldehyde and non-detection such as iso-valeraldehyde, n-valeraldehyde and o-tolualdehyde.

• Asian-Australasian Journal of Animal Sciences
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• 제30권5호
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• pp.720-727
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• 2017

Objective: The aim of this work was to determine the relationship between objective sensory descriptors and volatile flavour compound composition of Polish traditional dry-cured loin. Methods: The volatile compounds were investigated by using solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS). For sensory assessment, the quantitative descriptive analysis (QDA) method was used. Results: A total of 50 volatile compounds were found and assigned to 17 chemical families. Most of the detected volatile compounds derived from smoking, lipid oxidative reactions and seasoning (46.8%, 21.7%, and 18.9%, respectively). The dominant compounds were: aromatic hydrocarbon (toluene); alkanes (hexane, heptane, and 2,2,4-trimethylpentane); aldehyde (hexanal); alcohol (2-furanmethanol); ketone (3-hydroxy-2-butanone); phenol (guaiacol); and terpenes (eucalyptol, cymene, ${\gamma}-terpinen$, and limonene). Correlation analysis showed that some compounds derived from smoking were positively correlated with the intensity of cured meat odour and flavour and negatively with the intensity of dried meat odour and flavour, while terpenes were strongly correlated with odour and flavour of added spices. Conclusion: The analysed dry-cured loins were characterized by specific and unique sensory profile. Odour and flavour of studied loins was mainly determined by volatile compounds originating from smoking, seasoning and lipid oxidation. Obtained results suggest that smoking process is a crucial stage during Polish traditional dry-cured loins production.