• Korean Chemical Engineering Research
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• v.54 no.6
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• pp.753-761
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• 2016

Liquid-liquid extraction (LLE) can be used for the recovery of acetic acid from black liquor prior to bioethanol fermentation. Recovery of value-added chemicals such as acetic-, formic- and lactic acid using LLE from Kraft black liquor was studied. Acetic acid and formic acid have been reported to be strong inhibitors in fermentation. The study elucidates the effect of three reaction parameters: pH (0.5~3.5), temperature ($25{\sim}65^{\circ}C$), and reaction time (24~48 min). Extraction performance using tri-n-octylphosphine oxide as the extractant was evaluated. The maximum acetic acid concentration achieved from hydrolyzates was 69.87% at $25^{\circ}C$, pH= 0.5, and 36 min. Factorial design was used to study the effects of pH, temperature, and reaction time on the maximum inhibitor extraction yield after LLE. The maximum potential extraction yield of acetic acid was 70.4% at $25.8^{\circ}C$, pH=0.6 and 37.2 min residence time.

• Proceedings of the Korean Fiber Society Conference
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• 1999.10a
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• pp.407-410
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• 1999

• Analytical Science and Technology
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• v.29 no.4
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• pp.202-208
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• 2016

본 연구에서는 사료 첨가제로 이용되고 있는 유기산 7종(formic acid, malic acid, lactic acid, acetic acid, citric acid, fumaric acid, propionic acid)의 동시분석법 개발을 위한 연구를 실시하였다. 7종의 화합물은 표준물질의 Retention time과 UV spectra를 통해 구별하였고, 분석법 검증은 직선성, 민감성, 선택성, 정확성, 정밀성을 통하여 검증하였다. 그 결과로 LOD와 LOQ의 범위가 각각 43~26,755 μg/kg, 12-8,026 μg/kg으로 설정하였고, 평균 회수율이 79.3~95.2%로 우수하게 보였으며, intra-day, inter-day에 대한 전반적인 상대 표준 편차(%RSD)는 3.2% 미만으로 나타났다. 이와 같이 검증된 자료를 통해 유기산의 동시분석에 대한 직선성, 민감성, 선택성, 정확성 및 정밀성을 확인하였고, 높은 수준을 나타냄을 알 수 있었다. 이를 바탕으로 유기산이 검출되는 단미사료 46 가지를 분석에 적용하여 진행하였고, 정량과 동시분석 검출을 위한 방법은 RP-HPLC/UV 검출기를 이용하여 성공적으로 개발되었다. 따라서 본 연구결과를 바탕으로 하여 사료 중의 유기산의 분석이 신속하고 정확해졌을 뿐 아니라, 다른 종류의 사료 또한 이를 적용하여 효율적으로 이용할 수 있을 것으로 판단된다.

• Journal of the Korean Chemical Society
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• v.38 no.4
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• pp.271-275
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• 1994

The photochemical reaction of aqueous ethanol saturated with argon and carbon monoxide has been investigated using 184.9 nm UV light. The photochemical reaction of $1{\times}10^{-2}$ M aqueous ethanol saturated with argon results in the formation on the acetaldehyde and 2,3-butanediol. The irradiation of the solution saturated with carbon monoxide causes the formation of carbonylation and carboxylation products such as ${\alpha}$-hydroxypropionaldehyde, formaldehyde, glyoxal, formic acid, oxalic acid and glyoxylic acid in addition to above two products. But in the case of concentrated ethanol solutions, the irradiation did not give carbonylation and carboxylation products. The initial quantum yields of the products were determined and probable mechanisms for the reaction were presented on the basis of product analysis.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.2
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• pp.21-26
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• 2013

Conversion of fructose to 5-hydroxymethylfurfural (5-HMF) was investigated in dimethylsulfoxide (DMSO) solvent with increasing reaction temperatures and impact of residual water from dehydration reaction byproduct. To convert fructose to 5-HMF, increasing reaction temperature led more conversion to 5-HMF than lower temperature at the range of $120-150^{\circ}C$ in DMSO solvent. DMSO engaged in the acid-catalyzed dehydration and rearrangement reaction as acid and solvent. Increasing temperature led to more furanose structure than pyranose at the range of $30-80^{\circ}C$. Formed 5-HMF could be degraded to levulinic and formic acid at the presence of acid and water. Removal of water in reaction medium could prevent 5-HMF degradation.

• KSBB Journal
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• v.18 no.6
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• pp.473-478
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• 2003

The purpose of this study is to look for the optimal conditions of methane production. The conditions tested for methane production enhancement were temperature, pH, carbon source, nitrogen source, and inhibitor which can affects methane production. As a result, optimal conditions for methane production were 30$^{\circ}C$, neutral pH, methanol as a carbon source, NH$_4$Cl as a nitrogen source. 2-Bromoethanesulfonic acid was used as an inhibitor which can affects methane production. Existence in broth less than 10mM, inhibited methane production. Organic acid measurements revealed that formic acid exists in broth as majority.

• Journal of the Korean Society of Food Science and Nutrition
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• v.6 no.1
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• pp.17-20
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• 1977

Contents of free amino acids and organic acids in the leaves of Ailanthus altissima were surveyed through the course of this study. The results were as follows; 1. Lysine, histidine, arginine, tryptophan, aspartic acid, glutamic acid, threonine, serine, proline, glycine, alanine, valine, leucine, isoleucine, methionine, tyrosine and phenylalanine were presented in the leaves of A. altissima, and glutamic acid showed the highest amount and was more than about 48% of total free amino acids. 2. Fumaric acid was the major organic acid in the leaves of A. altissima, and also formic acid, acetic acid, maleic acid, succinic acid, oxalic acid, citric acid, tartaric acid and sorbic acid were determined, and two unknown were found.

• Journal of the Korean Society of Food Science and Nutrition
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• v.5 no.1
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• pp.61-64
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• 1976

A survey of the free amino acids and organic acids in the shoot of Phyllostachys edulis was made by means of amino acid autoanalyzer and gas chromatograph. The results of the survey are summerized as follows. 1. Eighteen amino acids found in bamboo shoot were lysine, histidine, arginine, tryptophan, aspartic acid, glutamic acid, threonine, serine, proline, glycine, alanine, valine, leucine, isoleucine, methionine, tyrosine and phenylalanine, and an unknown was found. Serine showed the highest amount and more than about 44% of total free amino acids. 2. Oxalic acid was the major organic acid, and formic acid, acetic acid, maleic acid, succinic acid, fumaric acid, citric acid, tartaric acid and sorbic acid were determined, and two unknown were found.

• Korean Journal of Food Science and Technology
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• v.36 no.1
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• pp.134-140
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• 2004

Optimal extraction method for antioxidant compounds from coat of grape dreg was established. Extracts were prepared with ethanol solutions containing phosphoric, formic, acetic, HCl, TFA, and citric acids. Antioxidant compounds of grape coat were determined by HPLC analysis and evaluated for antioxidizing effects using in vitro model system. Peonidin-3-glucoside content was the highest in 0.1% HCl-added ethanol extract. The extract prepared from pure ethanol without organic acids showed the highest content of cyanidin-3-glucoside among samples tested. Resveratrol and quercetin contents, the most important antioxidants, were highest in 0,1% HCl-added extract. Electron-donating ability was high in 0.1% acetic acid-added extract. SOD-like activities were 95.08% and 94.39% in 0.1% formic and 0.1% citric acid extracts, respectively. Inhibitory effects on peroxidation of egg yolk lecithin were observed in phosphoric (60.51%), citric (59,27%), and formic acid (56,77%) extracts. Hydrogen radical-scavenging activity was 59.47% in 0,1% HCl extract. Results suggest addition of 0.1% HCl in ethanol solution affords the highest yield in antioxidant compounds and antioxidant activities.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.1
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• pp.96-102
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• 2011

In this study, we examined the effects of formic acid administration to the drinking water on performance, intestinal microflora and carcass contamination in male broilers. A total of 312 day-old male broiler chicks were allocated to two groups with three replicates. The first group (control) received normal drinking water (pH 7.4) during the experiment. The second group consumed acidified drinking water (pH 4.5) after 5 d of age. At 43 d of age, twelve birds were randomly selected from the control group to determine the effect of acidified drinking water on carcass contamination. These birds were only given normal or acidified (pH 3) drinking water for 8 h prior to slaughter. The reduction of water pH from 7.4 to 4.5 significantly decreased body weights of male broilers at 21 and 42 d of age. However, no differences were observed between male broilers given normal and acidified drinking water in terms of feed intake, feed conversion ratio and mortality. The pH value of the gizzard contents was not significantly affected by acid water treatment. There were no significant differences in the intestinal population of E. coli, total organism and Salmonella between the groups. The total organism and E. coli counts of the carcass slightly decreased in the acidified group. No Salmonella was identified in carcass samples of any of the treatment groups. The results showed that drinking water acidification did not provide beneficial effects on performance, intestinal microflora and carcass contamination in male broilers.