• Membrane and Water Treatment
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• v.9 no.3
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• pp.137-146
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• 2018

Soil washing is one of the most frequently used remediation technologies for heavy metal-contaminated soils. Inorganic and organic acids and chelating agents that can enhance the removal of heavy metals from contaminated soils have been employed as soil washing agents. However, the toxicity, low removal efficiency and high cost of these chemicals limit their use. Given that humic substance (HS) can effectively chelate heavy metals, the development of an eco-friendly, performance-efficient and cost-effective soil washing agent using a nano-scale chelator composed of HS was examined in this study. Copper (Cu) and lead (Pb) were selected as target heavy metals. In soil washing experiments, HS concentration, pH, soil:washing solution ratio and extraction time were evaluated with regard to washing efficiency and the chelation effect. The highest removal rates by soil washing (69% for Cu and 56% for Pb) were achieved at an HS concentration of 1,000 mg/L and soil:washing solution ratio of 1:25. Washing with HS was found to be effective when the pH value was higher than 8, which can be attributed to the increased chelation effect between HS and heavy metals at the high pH range. In contrast, the washing efficiency decreased markedly in the low pH range due to HS precipitation. The chelation capacities for Cu and Pb in the aqueous phase were determined to be 0.547mmol-Cu/g-HS and 0.192mmol-Pb/g-HS, respectively.

• The Journal of Korean Medicine
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• v.30 no.5
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• pp.146-156
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• 2009

Objectives: The objective of this study was to investigate the antioxidant effects of manufactured Wen-pi-tang-Hab-Wu-ling-san (WHW$^{(R)}$) in vitro. Methods: WHW$^{(R)}$ was prepared by the pilot manufacture of WHW water extract from a GMP system appointed company. Antioxidative activities were determined by in vitro tests as follows: the scavenging activities of oxygen free radicals including 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, superoxide anion, hydrogen peroxide and nitric oxide radicals, as well as ferrous ion chelating capacity and Trolox equivalent antioxidant capacity (TEAC). Results: WHW$^{(R)}$ significantly scavenged oxygen free radicals such as DPPH (IC$_{50}$=115.28 $\pm$ 0.25 $\mu$g/$m\ell$), superoxide anion (IC$_{50}$=8.56 $\pm$ 0.08 $\mu$g/$m\ell$), hydrogen peroxide (IC$_{50}$=240.36 $\pm$ 3.41 $\mu$g/$m\ell$) and nitric oxide (IC$_{50}$=162.28 $\pm$ 0.21 $\mu$g/$m\ell$) radicals. WHW$^{(R)}$ also showed ferrous ion chelating activity (IC$_{50}$=543.19 $\pm$ 4.85 $\mu$g/$m\ell$) and Trolox equivalent effects (IC$_{50}$=45.311 $\mu$g/$m\ell$) in TEAC and ORAC assay, respectively. Conclusion: This study demonstrates that WHW$^{(R)}$ has strong antioxidative properties through free radical scavenging activity. These data suggest that WHW$^{(R)}$ be used as an antioxidant agent.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.6
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• pp.1097-1101
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• 2002

This study was conducted to investigate the efficacy of antioxidant ability and nitrite scavenging ability of Poria cocos Poria cocos mycelium and Poria cocos fermented with rice were extracted with water and ethanol for measurement of degree of fat acidification against fish oil. Lower TBARS values of Poria cocos mycelium and Poria cocos fermented with rice were shown compared with control. Iron chelating ability of Poria cocos mycelium against Fe$^{2+}$, Cu$^{2+}$ was higher than Poria cocos fermented with rice. Electron donating abilitv of water extract and ethanol extract of Poria cocos mycelium were 76.8% and 79.9%, respectively. Higher nitrite scavenging ability was shown at ethanol extract than water extract of Poria cocos mycelium.ium.

• Korean Journal of Materials Research
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• v.21 no.8
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• pp.468-475
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• 2011

[ $LaMeO_3$ ](Me = Cr, Co) powders were prepared using the polymeric precursor method. The effects of the chelating agent and the polymeric additive on the synthesis of the $LaMeO_3$ perovskite were studied. The samples were synthesized using ethylene glycol (EG) as the solvent, acetyl acetone (AcAc) as the chelating agent, and polyvinylpyrrolidone (PVP) as the polymer additive. The thermal decomposition behavior of the precursor powder was characterized using a thermal analysis (TG-DTA). The crystallization and particle sizes of the $LaMeO_3$ powders were investigated via powder X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and particle size analyzer, respectively. The as-prepared precursor primarily has $LaMeO_3$ at the optimum condition, i.e. for a molar ratio of both metal-source (a : a) : EG (80a : 80a) : AcAc (8a) inclusive of 1 wt% PVP. When the as-prepared precursor was calcined at $700^{\circ}C$, only a single phase was observed to correspond with the orthorhombic structure of $LaCrO_3$ and the rhombohedral structure of $LaCoO_3$. A solid-electrolyte impedance-metric sensor device composed of $Li_{1.5}Al_{0.5}Ti_{1.5}(PO_4)_3$ as a transducer and $LaMeO_3$ as a receptor has been systematically investigated for the detection of NOx in the range of 20 to 250 ppm at $400^{\circ}C$. The sensor responses were able to divide the component between resistance and capacitance. The impedance-metric sensor for the NO showed higher sensitivity compared with $NO_2$. The responses of the impedance-metric sensor device showed dependence on each value of the NOx concentration.

• Preventive Nutrition and Food Science
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• v.21 no.2
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• pp.110-116
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• 2016

This study was performed to evaluate and compare the antioxidant substance content and antioxidant activities of white (Superior) and colored (Hongyoung, Jayoung, Jasim, Seohong, and Jaseo) potatoes. The potatoes were extracted with 80% ethanol and were evaluated for the total polyphenol, flavonoid, and anthocyanin contents and for 1,1-diphenyl-2-picrylhydrazyl (DPPH)/2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity, reducing power, and ferrous metal ion chelating effect. The total polyphenol, flavonoid, and anthocyanin contents of Hongyoung and Jayoung were higher than white and other colored potatoes. All colored potato extracts, except for Jaseo and Seohong, showed higher ABTS radical scavenging activities than the general white potato extract. Hongyoung and Jayoung had the highest ABTS and DPPH radical scavenging activities. Optical density values for the reducing power of Jayoung and Jaseo at concentration of 2 mg/mL were 0.148 and 0.090, respectively. All colored potato extracts had lower ferrous metal ion chelating effect than the white potato. A significant (P<0.05) positive correlation was observed between total polyphenol content and total flavonoid content (r=0.919), anthocyanin content (r=0.992), and ABTS radical scavenging activity (r=0.897). Based on these results, this research may be useful in developing the Hongyoung and Jayoung cultivars with high antioxidant activities.

• The Korean Journal of Food And Nutrition
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• v.26 no.3
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• pp.398-403
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• 2013

To manufacture the fermented tea with hygienic quality, green tea was fermented using Bacillus subtilis, Saccharomyces cerevisiae and Lactobacillus bulgaricus and mineral composition, total amino acid content and antioxidative activity changes were evaluated during the fermentation period. Minerals detected in the fermented tea, the Ca, Fe, Zn, Mg and Mn minerals were detected. Ca and Mg are relatively large compared to other mineral content. Total amino acid content of the control was 3.57%, but total amino acid of fermented teas were higher (3.68~3.85%) during fermentation 20 days. Metal chelating activity of control was 55.11%, Metal chelating activity of the fermented tea using B. subtilis was the highest. In reducing power, O.D. value of the control was 2.27, three kinds of fermented tea were lower than that of control. The fermented teas increased lipid peroxidation inhibition compared to the blank test.

• Analytical Science and Technology
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• v.11 no.6
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• pp.452-459
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• 1998

Crosslinked chitin was prepared from epichlorohydrin and chitin which was isolated from waste marin source. The crosslinked chitosan were prepared by the deacetylation of the crosslinked chitin with a strong base. 2,2'-Iminodibenzoic acid-crosslinked chitosan was prepared by reacting 2,2'-Iminodibenzoic acid salt with crosslinked chitosan-Cl which was obtained by chlorination of crosslinked chitosan. The adsorptivity of Pb(II), Cu(II), Cd(II) was studied as a synthetic adsorbent. Experimental results for the adsorption and the recovery characteristics showed that the more pH increase, the more amount of adsorbed metal ion increase. Optimum adsorption time was 1 hr, and adsorption capacity was increased in order of $Cu^{2+}$<$Cd^{2+}$<$Pb^{2+}$, and recovery capacity was increased in order of $Cd^{2+}$<$Cu^{2+}$<$Pb^{2+}$.

• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1053-1060
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• 1996

$\beta$-ketohexanal as a chelating extractant was synthesized from the reaction of ethyl formate and methyl propyl ketone in the presence of sodium amide, and the equilibrium characteristics in the extraction of copper by $\beta$-ketohexanal-chloroform were investigated. The equilibrium constants such as the dissociation constant and the partition coefficients of $\beta$-ketohexanal, the stability constant and the partition coefficient of copper chelating complex, and the overall equilibrium constant in the extraction of copper were determined by spectrophotometric measurements, and the mechanism of extraction was proposed. The percent of extracted copper by $\beta$-ketohexanal-chloroform was near 100%, and the selective extraction of copper from Cu-Zn-Cd mixture was possible. Copper was found to be extracted as $CuR_2$ and the equilibrium reaction was expressed as $Cu^{2+}+2{\overline{HR}}{\rightleftarrows}{\overline{CuR{_2}}}+2H^+$.

• Korean journal of food and cookery science
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• v.32 no.4
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• pp.466-475
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• 2016

Purpose: This study investigated the quality characteristics and antioxidant effects of Yakju added with rose, camellia, or cockscomb flower during fermentation. Methods: The quality characteristics and antioxidant effects were estimated including pH, amino acidity, total acid, ethanol content, color value, sensory test, electric donating ability, nitrite-scavenging ability, and ferrous ion chelating effect. Results: The pH values of Yakjus added with rose, camellia, or cockscomb flower were decreased after 2 days of fermentation and then increased after 4 days of fermentation, with final pH ranging from 4.15 to 4.27. Total acid content and amino acidity were increased during fermentation. The ethanol content in Yakjus fermented with rose, camellia, or cockscomb flower was rapidly increased after 2 days of fermentation, reaching the maximum content of 19.1% after 8 days of fermentation. In color evaluation, the L values of Yakjus added with rose, camellia, or cockscomb flower did not changes during fermentation, whereas values of a and b were increased. Total phenolic compound contents in Yakjus added with rose, camellia, or cockscomb flower were 0.67, 0.59, and 0.52 mg/mL, respectively. Total flavonoid contents in Yakjus added with rose, camellia, or cockscomb flower were 0.20, 0.09, and 0.26 mg/mL, respectively. In sensory test, the overall acceptability of Yakjus added with cockscomb flower was higher than that of Yakju added with rose or camellia flower. However, the difference was not statistically significant (p<0.05). Electron donating ability and nitrite-scavenging abilities were the highest in Yakjus added with rose flower, whereas ferrous ion chelating effect was the highest in Yakjus added with cockscomb flower. Conclusion: These results indicated that Yakjus added with rose, camellia, or cockscomb flower might have valuable functional properties due to their antioxidant effects.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.1067-1070
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• 1997

Imunoglobulins from bovine plasma proteins were isolated by IMAC which $Cu^{2+}$ was chelated on a chelating sepharose fast flow gel. Most plasma proteins were eluted by 1st (0.01 M $Na_2HPO_4$, 0.5 M NaCl, pH 4.0) and 2nd elution buffers (0.01 M imidazol). According to the reverse phase HPLC analysis, it was found that proteins which were eluted by 1st elution buffer were mainly composed of serum albumin, while most IgG and transferrin were eluted by 2nd elution buffer. When protein fractions obtained by 2nd elution buffer was applied to ultra filtration system (molecular weight cut off: 100 kD), IgG was further purified. These results indicate that IMAC is an excellent tool for isolating imunoglobulins from plasma proteins.