• Journal of the Korean Society of Tobacco Science
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• v.7 no.1
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• pp.85-92
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• 1985

Extraction efficienties of volatile organic acids in tobacco leaves according to several extraction methods were investigated and contents of volatile organic acids in 16 kinds of tobacco leaf varieties were compared. Extraction efficiency according to simultaneous distillation and extraction was 5 to 10 times higher than that according to solvent extraction, steam distillation, essential oil extraction or continuous extraction and distillation. Total contents of volatile organic acids were 1.62 to 12.94mg per l00g of sample in aromatic tobacco varieties,0.12 to 2.08mg in flue-cured tobacco leaves, and trace in burleys. Among the Korean aromatic tobacco varieties, total contents of volatile organic acids in ST374-3 were the highest, 4.66mg per l00g of sample, and those in Sohyang and Hyangcho were low, 1.69mg and 1.62mg, respectively. Among flue-cured tobacco varieties, those in NC2326 were the highest, 2.08mg per 100g of sample, but those in the other varieties were not more than 0.80mg per 1 00g of sample. Total contents of volatile organic acids in acidic hydrolysis with 0.1 M tartaric acid were higher than in non-acidic condition in all kinds of tobacco varieties.

• YAKHAK HOEJI
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• v.39 no.3
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• pp.283-288
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• 1995

Rapid gas chromatographic profiling method was applied to saliva from healthy subjects for the analysis of free organic acids. Saliva samples were first saturated with NaHCO$_{3}$ and extracted with diethyl ether. The aqueous phase was solid-phase extracted using Chromosorb P as the adsorbent and diethyl ether as the eluent after the acidification and NaCl saturation, followed by triethylamine treatment. The resulting tiiethylammonium salts of acids were directly converted into stable tert.-butyl-dimethylsflyl derivatives, with subsequent analysis by dual-capiuary column gas chromatography and gas chromatograpy -mass spectrometry. From the ten saliva samples studied, twenty eight free organic acids including various fatty acids, hydroxy acids, dicarboxylic acids, md aromatic acids were tentatively identified. Among the acids identified , the concentration of lactic acid was highest for five saliva samples while $\alpha$-hydroxyisocaproic acid was most abundant for me sample, and succinic acid and glycolic acid for two samples. respectively. When the GC profiles were simplified to the corresponding acid retention index spectra of bar graphical form, they presented characteristic patterns for each individual.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.191-195
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• 2005

Experiment was conducted to establish the standard of quality evaluation in Korean cultivated peony roots. free sugars, free amino acids, organic acids and aromatic components, which were generally considered to be information components of five sensory test in peony roots, were examined. As free sugars, sucrose, glucose and fructose were identified in peony roots. $\gamma-aminoisobuturic$ acid, arginine and other 16 kinds of free amino acids were found in peony roots. The major organic acids of peony roots were oxalic acid, citric acid and malic acid. Eugenol and other 10 aromatic components were identified in peony roots by GC/MSD.

• Journal of Environmental Impact Assessment
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• v.30 no.2
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• pp.132-139
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• 2021

Laboratory-scale experiments were conducted to assess the effect of oxidative decomposition of polycyclic aromatic hydrocarbons (PAHs) in field soil using peroxy-acid. The study soil texture is sandy soil containing 19.2 % of organic matter at pH 6.8. Among polycyclic aromatic hydrocarbons (PAHs) in the study soil, the concentration of benzo(a)pyrene is 2.23 mg/kg which is three times higherthan the Korea standard level. Therefore benzo(a)pyrene was selected as the target study PAH for the treatment by peroxy-acid oxidation using peroxy-acid coupled with hydrogen peroxide, and the efficiency of the oxidative decomposition of benzo(a)pyrene was assessed for the different organic acids and dosages of an organic acid and hydrogen peroxide. Propionic acid among the tested organic acids showed the highest efficiency of benzo(a)pyrene reduction in the peroxyacid oxidation treatment and finally satisfied the Korea standard level.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2000.11a
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• pp.3-8
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• 2000

Chemical nature of nascent metal surfaces which is one of the important active sources for tribochemical reactions was investigated using a newly developed method. Some enhanced activities were observed. For example, organic compounds chemisorbed on nascent gold surfaces and aromatic compounds decomposed on nascent nickel surfaces resulting in hydrogen evolution. Non-polar compounds such as organic sulfides had a higher chemisorption activity on nascent steel surfaces than polar compounds such as fatty acids and phosphates. Organic sulfides reacted directly with nascent steel surfaces and the surface was covered with metal sulfides. The activity for the chemisorption of organic compounds was closely dependent on the electronic structure of metals. Although benzene chemisorbed very easily on nascent surfaces of transition metals, it did not chemisorb ell nascent surfaces of simple metals. Boundary lubricating behaviors of extreme pressure additives were explained on the bases of the chemical activities of nascent surfaces obtained in this investigation. Under mild conditions, polar compounds such as fatty acids and phosphates were effective for boundary lubrication, because surfaces are covered with oxide layers. On the other hand, sulfides were more effective under severe conditions where the oxide layers were removed and the nascent surfaces were formed.

• Journal of the Korean Society of Tobacco Science
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• v.6 no.2
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• pp.147-153
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• 1984

During curing of aromatic tobacco leaves, coloring temperatures were set at 26, 30, 34, 38 and $42^{\circ}C$, and also leaf drying temperatures were established at 35, 40, 45, 50, 55 and $60^{\circ}C$, respectively, to investigate the thermal effect on characteristics of cured leaves. Appearance of yellow color from green was accelerated, the contents of non-volatile organic and higher fatty acids in leaves tended to increase with the higher yellowing temperature. Quality by price per kg was best at 45-$50^{\circ}C$ and score of smoking test was highest at 40-$50^{\circ}C$ during leaf drying stage. The concentrations of non-volatile organic acids and volatile essential oil inclined to decrease, but a reverse in this trend with higher fatty acids as temperature increased during leaf drying stage. The difference of other components was discussed.

• Bulletin of the Korean Chemical Society
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• v.22 no.8
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• pp.850-856
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• 2001

This study investigates the ozonation kinetics of 2-chlorophenol in wastewater under acidic condition. Intermediates and by-products generated during the process were rigorously identified and quantified. The major by-products are four carboxylic acids: tartaric acid, oxalic acid, maleic acid, and hydroxymalonic acid. The generation of these organic acids is in agreement with theoretical predictions. But hydroxylated compounds are more favorable to produce than their corresponding non-hydroxylated ones. Based on the information concerning the generation of organic acids and other aromatic intermediates, the complete reaction pathways toward mineralization can be proposed and mathematically modeled. The fitted second-order rate constants are in the same order of magnitude with the results from other studies. Using these oxidation pathways and the corresponding kinetic model, by-products generated in ozonation process can be predicted. This can help in optimizing the design and operation of any subsequent treatment processes.

• Journal of the Korean Wood Science and Technology
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• v.21 no.3
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• pp.22-29
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• 1993

나뭇잎으로부터 발생되는 저분자량 유기산을 이온크로마토그래피를 이용하여 분석하였다. 이 방법은 자연상태의 나뭇잎 (needle litter)을 유기용매의 추출 없이 그대로 이용할 수 있어서 사용하기에 편리하다. 본 논문에서는 이온 크로마토그래피의 사용방법과 침엽수잎(Pacific Silver Fir)의 부후정도에 따른 유기산의 종류와 농도의 변이를 간략하게 소개한다. 초기의 침엽수잎 여과액으로부터는 $C_2$에서 $C_4$까지의 아세트산(acetic acid), 프로피온산(propionic acid), 옥살산(oxalic acid) 그리고 포름산(formic acid) 등이 주종을 이루지만 부후정도가 커짐에 따라 방향핵을 가진 방향핵 유기산(aromatic organic acid)이 발생한다.

• Journal of the Korean Chemical Society
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• v.32 no.2
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• pp.113-121
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• 1988

The retention mechanism and separation of various aromatic sulfonic and carboxylic acids on reversed-phase liquid chromatographic column were studied in the mobile phase containing dodecyltrimethylammonium bromide (DTAB). The retention mechanism was found to be followed the ion-interaction model where the DTAB occupies a primary layer at the stationary phase while the sample anions and other co-anions in the system compete for forming the secondary layer. The capacity factors of samples were influenced by the several factors such as pH, concentration of various organic solvents, co-anions in the mobile phase and functional groups in sample molecules. Some mixtures of organic samples were attempted to separate under optimum condition.

• Korean Journal of Food Science and Technology
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• v.32 no.5
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• pp.997-1001
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• 2000

The organic acids in 3 kinds of medicinal herbal extracts were screened and compared each other according to their organic acid contents by an efficient gas chromatographic method. It involves solid-phase extraction of organic acids using Chromosorb P with subsequent conversion to stable tert-butyldimethysilyl derivatives for the direct analysis by capillary column gas chromatography and gas chromatography-mass spectrometry. Total of 24 organic acids were reproducibly identified from 3 kinds of herbal extracts. When the GC profiles were simplified to their retention index spectra, characteristic patterns were obtained for each herb sample. As expected, three kinds of herbal extracts showed three distinct patterns.