• 한국물환경학회지
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• 제38권3호
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• pp.133-142
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• 2022

Natural organic matter (NOM) is a heterogeneous mixture of organic matter with various polarities and molecular weights in an aquatic environment. This study investigated the effects of separation conditions (resin volume, organic matter, etc.) and the repeated use of the resin for the fractionation of organic components in the DAX resin fractionation method. The distribution characteristics of the organic components ((hydrophilic [Hi], hydrophobic acid [HoA], and hydrophobic neutral [HoN]) under the derived fractionation conditions were also analyzed. Constant fractionation results (i.e. HoA/Hi ratio) were obtained in the column capacity factor (i.e. the packed resin volume) in the range of 50 to 100. The resin-packed column maintained constant separation efficiency for up to two repeated uses. The above conditions were applied to wastewater and stream water samples (before and after rainfall). The results showed that the concentration of organic matter in the wastewater effluent was 2-15 times lower with an increased ratio of hydrophilicity to hydrophobicity (i.e. Ho/Hi) compared to the influent depending on the industrial wastewater classification. Particularly, HoN was found to have a high content distribution, 10.2-50.4% of the total dissolved organic matter (DOM), in the effluents. For the stream water, the content of Hi or HoN increased significantly after rainfall, suggesting a correlation with the distribution characteristics of pollutants from the stream watershed. The results provide useful data to enhance the reliability of the DAX resin fractionation and its application to environmental samples.

• 환경위생공학
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• 제22권4호
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• pp.23-32
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• 2007

Changes in the characteristics of dissolved organic matter was studied at selected stations in the Nakdong river basin using physical and chemical methods. Characteristics of dissolved organic matters were analysed and assessed. Production of disinfection byproducts were also investigated. Distribution of the organic compounds according to the Molecular weight(MW) indicate that MWs higher than 100K were highest with cattle excrement wastewater and MW between 100-10K were highest with waters from forest streams. Low MW compounds (Jess than 1K) were highest with the effluents from environmental facilities. Results of resin fractionation study show that acidic hydrophobic substances(AHS) were dominant in many stations. The values were higher in the samples from mainstreams and sidestreams where the influence of organic matter is higher than the water from environmental facilities. Hydrophilic neutral substances(HoN) such as hydrocarbon, pesticides and detergents were higher in the wastewater treatment facilities. HoN values of water from the forest streams were 4.7% indicating there is no synthetic pollutant.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.138-138
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• 2006

• 한국자원식물학회지
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• 제27권6호
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• pp.635-641
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• 2014

Scutellaria baicalensis $G_{EORGI}$ (Scutellariae Radix) has been used to clear heat and to dry dampness in the stomach or intestines, which manifests as diarrhea or dysenteric disorder. In this study, we investigated the effective preparation of active components in Scutellariae Radix using the methods of solvent extraction and absorption fractionation for the development of new functional food or pharmaceuticals. The marker substances, baicalin, baicalein, wogonoside, and wogonin were directly isolated from the Scutellariae Radix. There chemical structures were elucidated by spectroscopic analysis. The Scutellariae Radix was extracted with hot water. To enhance yield of flavonoids in Scutellariae Radix, the hot water extract was dissolved in ethanol with concentration dependent manner. The precipitates were separated using centrifugal techniques at 10,000 rpm. Supernatant liquid was applied to the HPLC for quantification of major compounds. Separately, the hot water extract was absorbed on Diaion HP-20 resin. And then, the absorbed fraction was eluted with methanol for HPLC. The contents of baicalin, baicalein, wogonoside and wogonin in different treatment methods were analyzed by HPLC. Total amount of four major components were 16.9% in 50% ethanol extract, 21.7% in 70% ethanol extract, 20.5% in 90% ethanol extract, and 39.3% in absorbed fraction of Diaion HP-20 resin. In these results, we found that resin absorption method is suitable for the extraction of enriched flavonoids from Scutellariae Radix.

• 한국물환경학회지
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• 제26권6호
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• pp.976-985
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• 2010

In this study, characteristics of dissolved organic matter (DOM) from Lake Paldang and seven other DOM sources (lake plankton, plants, soil, composite, treated sewage) were studied using XAD resin fractionation and 28-day microbial incubation experiment. Distribution patterns of DOM-fractions, which include hydrophilic acids (HiA), hydrophilic bases (HiB), hydrophilic neutrals (HiN), hydrophobic acids (HoA), hydrophobic neutrals (HoN) and the extent of DOM biodegradation (i.e., biodegradability) were different depending on the origins of the DOM samples. The DOM distribution pattern and the biodegradability were found to be effective for distinguishing the different DOM sources. The biodegradability (%) had negative correlations with the content (%) of hydrophobic fractions (Ho) and specific UV absorbance of DOM, which indicate that the Ho fractions contain more aromatic carbon structures and relatively stable during biodegradation, irrespective of the sources. To gain additional insight into the microbial transformation of the DOM, we also investigated the changes in the fraction's distribution for plankton, leaf litter and composite samples after the incubation. The results showed that biodegradation of hydrophilic fraction (Hi) causes an increase in the proportion of Ho (HoA, HoN), while biodegradation of HoA increases the HoN production.

• Journal of the Korean Wood Science and Technology
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• 제51권1호
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• pp.38-48
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• 2023

Two important steps in utilizing technical kraft lignin (KL) from black liquor to synthesize lignin-phenol-formaldehyde (LPF) resin are its extraction via precipitation and fractionation. However, the effects of precipitation pH and acetone fractionation on the characteristics of hardwood KL have not been studied for LPF resins. Therefore, this paper reports the effects of the precipitation pH of black liquor and acetone fractionation on the characteristics of KL from mixed hardwood species for LPF resins. The precipitation was conducted at various pH levels from 3 to 9 of black liquor to obtain crude KL (C-KL), which was used in acetone fractionation to produce acetone-soluble KL (AS-KL) and acetone-insoluble KL (AI-KL). Precipitation at pH 3 and 9 produced the highest and lowest yields of C-KL, respectively. As expected, the C-KL infrared spectra were similar regardless of the precipitation pH levels. As the pH increased, the molecular weight of C-KL increased. However, the molecular weight of AS-KL and AI-KL after acetone fractionation increased to a maximum of 4,170 and 47,190 g/mol at pH 7, then decreased to 3,210 and 19,970 g/mol at pH 9, respectively. The smallest molecular weights of AS-KL and AI-KL were 3,210 and 15,480 g/mol and were found at pH 9 and 3, respectively. These results suggest that both AS-KL at pH 9 and AI-KL at pH 3 have good potential as starting lignins for synthesizing LPF resins that require cross-linking for polymerization.

• Bulletin of the Korean Chemical Society
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• 제21권1호
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• pp.69-74
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• 2000

Applicability of Thermal field flow fractionation (ThFFF) was investigated for the analysis of masticated natural rubber (NR) adhesives produced bya hot melt mastication process. An optimum ThFFF condition for NR analysis was found by using tetrahydrofuran (THF) as a solvent/carrier and a field-programming. Low flowrate (0.3 mL/min) was used to avoid stopping the flow for the sample relaxation. Measured molecular weight distribution was used to monitor degradation of rubber during the mastication process. Rubber samples collected at three different stages of the mastication process and were analyzed by ThFFF. It was found that in an anaerobic process rubber degradation occurs at the resin-mixing (compounding) zone as well as in the initial break-down zone, while in an aerobic process most of degradation occurs at the initial breakdown zone. It was also found that E-beam radiation on NR causes a slight increase in the NR molecular weight due to the formation of a branched structure.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 1999년도 Pre-symposium of the 10th ISWPC Recent Advances in Paper Science and Technology
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• pp.254-258
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• 1999

The distribution of anionic groups in the fibers, the fines, the colloidal fraction and the dissolved fraction, respectively, of thermomechanical pulp (TMP) suspensions was determined and peroxide bleaching of spruce TMP were also studied. Spruce TMP was extracted with hexane, treated with alkali, or bleached with peroxide. Suspensions made at pH 5.5 were fractionated into long fibres, large fines, small fines, a colloidal fraction and a dissolved fraction. The charge of the fractions was determined using polyelectrolyte titration. To determined the origin of the charges, the contents of fatty acids, resin acids and acidic units in hemicelluloses in the different fractions were determined by has chromatography. Extraction of TMP with hexane prior to fractionation increased the measured charge of the fibres. The removal of the wood resin probably uncovered some carboxyl groups on the fibre surfaces, or improved th e penetration of polybrene into the pores of the fibres. The charge of the fines and the colloidal fraction was lower when the wood resin had been removed. Alkaline treatment of the TMP increased the charge of the fibres and fines, mainly because of demethylation of pectins. Alkaline treatment increased the charge also of the dissolved fraction, because of the release the charge also of the dissolved fraction, because of the release of pectic acids into the water phase. Alkaline peroxide bleaching further increased the charge of fibres and the dissolved fraction, most likely because of lignin oxidation. The charge of the colloidal fraction, consisting mainly of wood resin, was only slightly affected by alkaline treatment and peroxide bleaching. The anionic groups in TMP suspensions were mainly free uronic acids in the hemicelluloses. The contribution from the fatty and resin acids was substantial only for the colloidal fraction.

• Journal of Applied Biological Chemistry
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• 제51권1호
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• pp.36-44
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• 2008

Organic forms of arsenic (As) were determined through fractionation procedure of soil organic matter (SOM) in soil, sediments and mine tailing samples from the Myungbong, Dongil, and Okdong mining areas of southern Korea. An alkaline extraction method was applied to soil samples followed by the fractionation procedures of SOM by the DAX-8 and XAD-4 resin adsorption method. Major fraction of organic As species (42% to 98%) was found in acid-soluble fraction, whereas minor fraction (0.1 % to 67.8%) was present in the humic-associated As. In acid-soluble fractions, the transphillic- and hydrophilic-associated As were dominant in addition to As binding with humic and fulvic SOM. Arsenic binding was the strongest between pH 6 to 8 and reduced to about 70% at both low and high pH regions. The amount of both transphillic and hydrophillic associated As was less changed than humic and fulvic-associated As, in both low and high pH regions. This apparently indicates that As has stronger affinity towards hydrophillic rather than hydrophobic organics. From the experimental observation of As-binding SOM in natural soil, the ligand exchange model may be a feasible explanation of transphillic and hydrophillic affinity of As.

• Mycobiology
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• 제44권4호
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• pp.338-342
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• 2016

The culture filtrate of Lentinula edodes shows potent antimicrobial activity against the plant pathogenic bacteria Ralstonia solanacearum. Bioassay-guided fractionation was conducted using Diaion HP-20 column chromatography, and the insoluble active compound was not adsorbed on the resin. Further fractionation by high-performance liquid chromatography (HPLC) suggested that the active compounds were organic acids. Nine organic acids were detected in the culture filtrate of L. edodes; oxalic acid was the major component and exhibited antibacterial activity against nine different phytopathogenic bacteria. Quantitative analysis by HPLC revealed that the content of oxalic acid was higher in the water extract from spent mushroom substrate than in liquid culture. This suggests that the water extract of spent L. edodes substrate is an eco-friendly control agent for plant diseases.