• The Journal of Natural Sciences
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• v.10 no.1
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• pp.17-21
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• 1998

Numerous chemicals were tasted to show antiviral activity in vitro against tobacco mosaic virus (TMV). With a brief exposure of TMV to 1 N HCl or 1-0.1 N NaOH, Virions and their encapsidated RNAs were degraded completely and rapidly. When TMV was exposed to 0.1 N HCl, the hydrolysis of viral capsid in 5 min after treatment was observed in the 1% agarose gel. Virions and their encapsidated RNAs were not degraded by 0.01N HCl of 0.01N NaOH. These characteristics indicate that a short exposure to optimal concentration of acid or base is of practical value in eliminating infectious virus. The treatment of 50% isopropanol or UV light did not damage in viral integrity or their encapsidated RNAs. Disinfection of the agricultural tools and laboratory equipments using appropriate disinfectants is necessary to prevent cross contamination if farm and laboratory.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.916-918
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• 2002

The effect of acid hydrolysis on isoflavone contents of defatted soybean flour (DSF) was investigated in this study. Isoflavone analyzed were daidzein, genistein, glycitein, daidzein, genistein and glycitein with using HPLC. The DSF suspension was heated at $95^{\circ}C$ for 4 hour with addition of HCl (0.25-3.00 N) and analyzed isoflavone. The results showed that the total isoflavone was increased as the HCl concentration increased up to 1.0 N HCl during heating, indicating conversion of glucoside isomers of isoflavone to its aglycons. However, higher concentration than 1.0 N HCl caused a relatively fast decrease in isoflavone after 4 hour of heating. These results were probably caused by degradation of isoflavone by high concentration of acid during heating. The glucosides of isoflavone were steadily decreased while its aglycons were rather increased during $1.0{\sim}2.0$ hour of heating.

• Nuclear Engineering and Technology
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• v.16 no.2
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• pp.58-63
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• 1984

Paper electrophoretic separation of octahedrally bonded (Ruc $l_{6}$ )$^{3-}$ has been carried out by using the specially designed migration apparatus. The supporting electrolyte solutions are as follows: 0.1M-HCl $O_4$, 0.05 M-HCl+0.09M-KCl, 0.1M-HCl, 5$\times$10$^{-3}$ M-NTA, 0.01M-HCl, 0.01M-HCl $O_4$, 0.01M-citric acid, 0.01M-K $H_2$P $O_4$+0.01M-N $a_2$HP $O_4$, 0.05M-borax, 0.025M-N $a_2$C $O_3$+0.025M-NaHC $O_3$, 0.01M-N $a_3$P $O_4$, 0.01M-NaOH and 0.1 M-NaOH. The (Ruc $l_{6}$ )$^{3-}$ appears in 2 to 4 peaks and is found in several chemical species such as (RuCl ($H_2O$)$_{5}$ )$^{2+}$, cis and trans (RuC $l_2$($H_2O$)$_4$)$^{1+}$, (RuC $l_3$($H_2O$)$_3$)$^{0}$ , (RuC $l_4$($H_2O$)$_2$)$^{1-}$, (RuC $l_{5}$ ($H_2O$))$^{2-}$ and (RuC $l_{6}$ )$^{3-}$. The retention value has been found to be highest in the 0.025M-N $a_2$C $O_3$+0.025M-NaHC $O_3$ electrolyte solution.n.

• Animal Bioscience
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• v.36 no.3
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• pp.492-497
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• 2023

Objective: The objectives were to demonstrate that the nitrogen and energy in pig urine supplemented with hydrochloric acid (HCl) are not volatilized and to determine the minimum amount of HCl required for nitrogen preservation from pig urine. Methods: In Exp. 1, urine samples of 3.0 L each with 5 different nitrogen concentrations were divided into 2 groups: 1.5 L of urine added with i) 100 mL of distilled water or ii) 100 mL of 6 N HCl. The urine in open plastic containers was placed on a laboratory table at room temperature for 10 d. The weight, nitrogen concentration, and gross energy concentration of the urine samples were determined every 2 d. In Exp. 2, three urine samples with different nitrogen concentrations were added with different amounts of 6 N HCl to obtain varying pH values. All urine samples were placed on a laboratory table for 5 d followed by nitrogen analysis. Results: Nitrogen amounts in urine supplemented with distilled water decreased linearly with time, whereas those supplemented with 6 N HCl remained constant. Based on the linear broken-line analysis, nitrogen was not volatilized at a pH below 5.12 (standard error = 0.71 and p<0.01). In Exp. 3, an equation for determining the amount of 6 N HCl to preserve nitrogen in pig urine was developed: additional 6 N HCl (mL) to 100 mL of urine = 3.83×nitrogen in urine (g/100 mL)+0.71 with R² = 0.96 and p<0.01. If 62.7 g/d of nitrogen is excreted, at least 240 mL of 6 N HCl should be added to the urine collection container. Conclusion: Nitrogen in pig urine is not volatilized at a pH below 5.12 at room temperature and the amount of 6 N HCl required for nitrogen preservation may be up to 240 mL per day for a 110-kg pig depending on urinary nitrogen excretion.

• The Korean Journal of Food And Nutrition
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• v.16 no.4
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• pp.388-396
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• 2003

The freeze dried young antler residue was extracted by proteases and hydrochloric acid(HCl). The young antler was extracted by water at 50$^{\circ}C$ and the residue was reacted by proteases for 5 hours at 50$^{\circ}C$. The extraction rate of its residue was 32.8%(absorbance 3.61 at 280nm) of bacteria protease, 23.8%(absorbance 0.69) of papain, and 31.2% (absorbance 2.96) of pepsin. The young antler was extracted by boiling water and the residue was reacted by proteases for 5 hours at 50$^{\circ}C$. The extraction rate of its residue was 45.0%(absorbance 3.61) of bacteria protease, 30.4%(absorbance 0.33) of papain, and 51.2% (absorbance 2.77) of pepsin. The result of HPLC analysis reveals that in 50$^{\circ}C$ water extract and boiling water extract, all high molecular peak was reduced under MW 1,000 by proteases. The result from the extract of young antler residue reacted by HCl for 5 hours at 50$^{\circ}C$ shows that its extraction rate was 45% (absorbance 0.78) in concentration of 0.1N HCl, 61% (absorbance 1.82) in 0.2N, 81% (absorbance 2.29) in 0.4N, and 82.0% (absorbance 3.28) in 2.0N. The result of HPLC analysis also reveals that in the extract by 0.8N HCl, the peak of about MW 70,000 accounted for 78% in total. Protein content of the extract by 0.8N HCl was 8.2%, and content of amino acid was 81.6%, ash was 1.3%, and mineral contents were 0.1 % of Ca, 2.3% of P, 0.8 % of Mg, 3.4% of Na, 0.002% of F by dry base.

• Journal of the Korean Chemical Society
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• v.29 no.2
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• pp.178-182
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• 1985

The purpose of this study was to develop a separation method of Zn(II), Cu(II) and Mg(II), by ion exchange chromatography using cation exchange resion (Dowex 50w${\times}$8, 80-100 mesh) and anion exchange (Amberlite IRA-400). Ion exchange resions were packed into 25 ${\times}$ 2cm ID column and flow rate was controlled to 0.30 ml/min. Good eluents for separation of nonferrous metal ions such as Zn(II), Cu(II), Mg(II) were as follow: 0.5M $NaNO_3$ (pH 3.1), 0.2~0.5M HCl + 50~60% Acetone, and 1M HAc + 0.1M NaAcf(pH 3.7) aqueous solution. The mixed solution of 0.1M NaAc(pH 3.7), 0.5M HCl + 50% Acetone were found to be the best eluent for step elution. Analysis of metals were determined by atomic absorption spectrophotometer. In addition, separated Zn(II) fraction was obtained by eluted with 0.12N HCl and 1.5N $NH_4OH$ aqueous solution. This solution was titrated by the E. D. T. A.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.8
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• pp.787-798
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• 2005

The objectives of this study were to assess extraction kinetics of heavy metals with extraction times and to assess extraction efficiencies of heavy metals with concentrations and kinds of washing solutions. Target materials were obtained from disused metal mines. Washing solutions were water, HCl(0.1, 0.3, 1.0 N), EDTA(0.01, 0.05, 0.1 M), and sodium dodecyl sulfate(SDS, 0.1. 0.5, 1.0%). Extraction efficiencies of heavy metals by water and SDS were below 1%, and extraction efficiencies of Zn and Cd were higher than those of Pb and Cu. As results, water and SDS were not effective in extracting heavy metals from mine tailings as washing solution, but extraction efficiencies of Pb and Cu with SDS solution increased as extraction time increased. Extraction kinetics of heavy metals with HCl and EDTA were faster than those with water and SDS. The majority of heavy metals were extracted within 6 hours, and extraction kinetics was almost independent of the solution concentration. Extraction kinetics of heavy metals after 6 hours was slow, but extraction kinetics was dependent on the solution concentration. Also, as concentrations of HCl and EDTA solution were stronger, heavy metals were extracted rapidly and extraction efficiencies were increased. The extraction efficiency was high in order of Cd>Pb>Zn>Cu in using 1.0 N HCl, and Pb>Cd>Zn>Cu in using 0.1 M EDTA. Consequently, extraction effectiveness was highest for Pb in using HCl, and for Pb and Cd in using EDTA with concentration increase. Extraction time of over 6 hours was not effective in extracting heavy metals.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.6-8
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• 2005

The forest soils of 92 sites in Korea were analyzed to survey heavy metal background levels using aqua regia digestion method and 0.1N HCl extraction method. From these results, the average natural contents of heavy metals were Cd 0.287, Cu 15.26, Pb 18.43, Cr 25.36, Zn 54.27, Ni 17.68mg/kg for aqua regia method, and Cd 0.040, Cu 0.48, Pb 3.06, Cr 0.09, Zn 1.54, Ni 0.27mg/kg for 0.1N HCl extraction method. The range of correlation coefficients between heavy metal contents obtained from two methods(aqua regia and 0.1N HCl) was significant as $0.24{\sim}0.88$, and the correlation coefficients were decreased in order of Cd, Pb, Cu, Ni, Cr, Zn.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.2
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• pp.77-86
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• 1990

The residue after hot water extraction of blue crab, Portunus trituberculata, was hydrolyzed for utilizing the byproducts as seasonings. The acid(5N HCl) hydrolyzates were then neutralized with $Na_2CO_3$, 5N NaOH or 5N NaOH hydrolyzate, while the alkali hydrolyzates (5N NaOH) were also neutralized with 5N HCl or 5N HCl hydrolyzate. The total nitrogen and formol nitrogen contents increased, and the platability of the hydrolyzates was also enhanced by neutralization. The released amino acid contents from the neutralized hydrolyzates with $Na_2CO_3$, 5N NaOH and 5N NaOH hydrolyzate were $2,274mg\%,\;2,105.0mg\%$ and $2,683.5mg\%$, respectively. Amino acid contents from the neutralized hydrolyzates with 5N HCl and 5N HCl hydrolyzate were $1,352.5mg\%$ and $2,498.8mg\%$, respectively. In the decolorization of hydrolyzates using decolorization agent, powdered active carbon showed good decolorizing effect. Powdered active carbon decreased total nitrogen and formol nitrogen contents in direct relationship to the increase in its concentration. The effective concentration of active carbon used as decolorization agent showed as $1\~2\%$ of the crab hydrolyzate. Salt contents could be decreased at 37 brix by desalination method such as the evaporation of the hydrolyzate contents.

• Analytical Science and Technology
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• v.23 no.1
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• pp.68-73
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• 2010

In order to develop the square wave voltammetric method determining cimetidine in an ampoule for injection, $5.00{\times}10^{-4}\;M$ cimetidine HCl solutions prepared with phosphate buffers of various pH values (3.01~8.97) were investigated by SWV. The well defined single peak due to the electrochemical reduction of -C=N-C$\equiv$N- in the structure of cimetidine moved towards the cathodic direction by -0.051V/pH as the pH values were increased indicating the involvement of hydrogen in its reduction. The calibration curves of cimetidine HCl in the concentration range between $1.00{\times}10^{-5}\;M$ and $5.00{\times}10^{-3}\;M$ prepared using three phosphate buffers yielded the slopes of 127,407nA/M (pH 3.01), 115,125nA/M (pH 5.00) and 111,287nA/M(pH 7.00) with excellent linearities of $R^2{\geqq}0.9997$. When one ampoule of Tagma Inj.$^{(R)}$ was analyzed by standard addition method by SWV, the within-day precision study (n=4) on the day of sample preparation resulted in the contents of cimetidine as $203{\pm}3.8\;mg$ (102% of the specified contents, RSD of 1.9%) and the inter-day precision (n=4) through 5 days was reasonable as 1.3% of RSD.