• Analytical Science and Technology
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• v.10 no.1
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• pp.35-42
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• 1997

The sample pretreatment technique using a high pressure acid digestion bomb for the analysis of ceramic capacitor materials, such as barium titanate and PZT, was studied. When the concentrations of hydrochloric acid were varied with the addition of nitric acid or distilled water, quantitative measurements for those samples were carried out using inductively coupled plasma atomic emission spectrometry. From this experiment the results indicate that most of elements, such as Ba, Mn, Zn, Si, etc., aren't affected by the concentration of hydrochloric acid but Nb and Zr are very susceptable to it. It however turns out that the digestion time relatively gave little effects on the analytical result. In case of Nb the ratio of hydrochloric acid to water should be greater than 3:1(v / v) for the best analytical result. For the Pb determination use of diluted hydrochloric acid compared to the mixture of nitric acid and hydrochloric acid showed a better analytical result.

• Analytical Science and Technology
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• v.20 no.2
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• pp.131-137
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• 2007

The urania-gadolinia fuels were dissolved with nitric acid. The analytical conditions of ICP-AES for the direct determinations of gadolinium in the uranium matrices without separation process were investigated. Based on the effect of uranium on gadolinium intensity, the best wavelength for gadolinium was 336.223 nm. The relative deviation of two methods, direct and indirect measurements with anion exchange chromatography, was less than 5 %. Therefore it was possible for this procedure directly to measure 5~10 wt.% of gadolinium in urania-gadolinia fuels without separation by ICP-AES.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.442-442
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• 2008

Hydrogen was produced by water plasma excited in very high frequency inductively coupled tube reactor. Mass spectrometry was used to monitor gas phase species at various process conditions. Water dissociation rate depend on the process parameters such as ICP power, flow-rate and pressure. Water dissociation percent in ICP reactor decrease with increase of chamber pressure and $H_2O$ flow rate, while increase with increase of ICP power. In our experimental range, maximum water dissociation rate was 65.5% at the process conditions of 265 mTorr, 68 sccm, and 400 Watt. The effect of $CH_4$ addition to a water plasma on the hydrogen production has been studied in a VHF ICP reactor. With the addition of $CH_4$ gas, $H_2$ production increases to 12% until the $CH_4$ flow rate increases up to 15 sccm. But, with the flow rate of $CH_4$ more than 20 sccm, chamber wall was deposited with carbon film because of deficiency of oxygen in gas phase, hydrogen production rate decreased. The main roles of $CH_4$ gas are to reacts with O forming CO, CHO and $CO_2$ and releasing additional $H_2$ and furthermore to prevent reverse reaction for forming $H_2O$ from $H_2$ and $O_2$. But, $CH_4$ addition has negative effects such as cost increase and $CO_x$ emission, therefore process optimization is required.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.4
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• pp.564-572
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• 2015

Nutritional compositions, volatile compounds, and sensory attributes of Cynanchi wilfordii Radix were analyzed in order to examine its practical utilization as a food resource. In the proximate analysis, protein and lipid contents were shown to be 14.6 and 5.0 mg/100 g, respectively, in C. wilfordii Radix. Potassium was the most predominant mineral (809 mg/100 g), as determined by inductively coupled plasma-optical emission spectrometry in parallel with microwave acid digestion. Total phenolic content was found to be 410 mg/100 g. Further, arginine and linoleic acid were the most abundant amino acid and fatty acid of C. wilfordii Radix, respectively. To examine its functional properties, classical 2,2-diphenyl-1-picrylhydrazyl (DPPH) analysis was performed. As a result, the concentration of C. wilfordii Radix required to scavenge 50% of DPPH radicals was 1.16 mg of dried material. Lastly, in olfactory and sensory tests, ${\beta}$-eudesmol (woody odor) was the major flavor compound responsible for the bitter taste and sensory attributes of C. wilfordii Radix. Taken altogether, the above results provide important preliminary results for utilization of C. wilfordii Radix as a food resource.

• Journal of Korea Soil Environment Society
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• v.5 no.2
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• pp.67-85
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• 2000

Fifty seven soil samples were collected from the paddy soil filled with tailings in the vicinity of the Seosung Pb-Zn mine. Those samples were analyzed for As, Cd, Co, Cr, Cu, Pb, and Zn in order to investigate heavy metal pollution levels in the paddy soil. Analyses of the soil samples were carried out using Inductively Coupled Plasma Atomic Emission Spectrometry(ICP-AES) . Paddy soils show pH range from 6.55 to 8.26. X-ray diffraction analyses of the paddy soil indicate that the soils consist predominantly ankerite, siderite, quartz, mica, and clay minerals with minor amounts of amphibole and chlorite. The mineral composition of the waste rocks consists of massive galena, sphalerite, and minor amounts of pyrite, arsenopyrite, chalcopyrite, calcite, siderite, Pb-sulfosalt, and marcasite. The paddy soils were significantly contaminated by heavy metals(average concentrations, As: 334.4 ppm, Cd: 37.6 ppm, Co: 15.7 ppm, Cu: 214.1 ppm, Pb: 4,612 ppm, and Zn: 4,468 ppm).

• Journal of Environmental Health Sciences
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• v.43 no.4
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• pp.257-266
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• 2017

Objectives: The hazardous metals content of medicinal herbs distributed in the Daegu area was investigated, and the place of origin and the content of herbicides and medicinal components were studied. Methods: An analysis of hazardous metals content (10 types) was carried out on 164 samples of 99 types of herbal medicines. Among the total samples, 45 were domestic and 119 were imported. Hg was analyzed by the amalgamation method. Other hazardous metals content (nine types) was digested using the microwave method and measured by inductively coupled plasma optical emission spectrometry (ICP-OES). Results: The mean values of the hazardous metals content in the herbal medicines were Pb 1.0833 mg/kg, As 0.0136 mg/kg, Cd 0.0840 mg/kg, Cr 3.7120 mg/kg, Cu 4.2666 mg/kg, Mn 40.080 mg/kg, Ni 1.4330 mg/kg, Sb 0.1053 mg/kg, Al 202.64 mg/kg and Hg 0.0062 mg/kg. Three of the samples violated the Ministry of Food and Drug Safety (MFDS) regulatory guidance on cadmium (less than 0.3 mg/kg). The measured values of heavy metals (Pb, As, Cd, Hg) showed levels below the recommended levels for herbal medicines in MFDS regulatory guidance. In the comparison of domestic samples with imported herbal medicines, it was found that one domestic and two imported samples surpassed the maximum residue limits for cadmium. The median values of the hazardous metals detected in the three medicinal parts of the root, leaf (branch), and flower (seed and fruit) were as follows. Cr, Ni, Sb and Al were highly detected in roots, Pb, Cd, Mn, Hg in leafs (branch), and As, Cu in flowers (seed and fruit). Conclusion: There were various kinds of hazardous metals which were detected at high levels according to the place of origin of the medicinal herb and the parts the plant. For hazardous metals for which no acceptance criteria have been established, safety standards should be further studied and managed to ensure the safety of herbal medicines.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.8 no.2
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• pp.196-208
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• 1998

To improve the quality of environmental measurements and evaluation of the workplace air in the pigment manufacturing industries, we analyzed metal(chromium, cadmium, lead, iron, cobalt, manganese, antimony, titanium, arsenic, and selenium) concentrations by ICP-AES in sixty seven samples of inorganic bulk pigments which are produced and/or used in Korea. We also collected MSDS which has to be supplied by manufacturer and/or supplier and posted in the workplace according to the Hazard Communication Standards, and compared the number of metals listed in each MSDS with the number of metals determined by ICP-AES. Results were as followed; 1. Among seventeen yellowish-colored samples, chromium(2~19%) and lead(0.1~61%) were the two major metals. In thirteen reddish-colored samples, iron was the major component with 37~81%. Cobalt and manganese were detected in blue-colored samples with less than 1%, while antimony and titanium were the major two metals in white-colored pigments with 178~300 ppm and with 36~65%, respectively. 2. In area samples collected in workplace air(one pigments producing factory and five retailer stores), iron and manganese were detected but the concentrations not exceeded the TLVs(1 and $5mg/m^3$, respectively). In three of fifteen samples, the concentrations of lead exceeded the TLV ($0.05mg/m^3$). 3. Two out of seven companies provided MSDS, and the average provision rate was 22.4%. And the coincidence rate of the number of metals referenced in MSDS and determined by ICP-AES mostly accorded, but in one sample, different metal was detected from MSDS. In summary, metals have to be concerned in evaluation of the workplace air dealing with compounds of inorganic pigments dust are cobalt, chromium, iron, manganese, lead and antimony, and these are simultaneously determined by ICP-AES. Taking this opportunity, it is needed to reinforce that the personnel is to be concerned about prevention of workers' ill health regarding to provision of MSDS.

• Analytical Science and Technology
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• v.16 no.2
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• pp.117-124
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• 2003

Oxygen to metal ratio has been measured by wet and dry chemical analysis to study the properties of sintered $UO_2$ pellets and $U_3O_8$ in the lithium reduction process of spent pressurized water reactor fuels. Uranium dioxide pellets simulated for the spent PWR fuels with burnup values of 20,000~60,000 MWd/MtU were prepared by mixing $UO_2$ powder and oxides of fission product elements, pelleting the powder mixture and sintering it at $1,700^{\circ}C$ under a hydrogen atmosphere. For wet chemical analysis, the simulated spent fuels were dissolved with mixed acid (10 M HCl : 8 M $HNO_3$, 2.5 : 1, v/v) using acid digestion bomb technique. The total amount of uranium and fission products added in the simulated spent fuels were measured using inductively coupled plasma atomic emission spectrometry. Weight change of the simulated fuel during its oxydation was measured by thermogravimetry and then the O/M ratio result was compared to that obtained by wet chemical analysis. Influence of $Mo_{0.4}-Ru_{0.4}-Rh_{0.1}-Pd_{0.1}$, quaternary alloy, on the determination of O/M ratio was investigated.

• Journal of Microbiology and Biotechnology
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• v.24 no.6
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• pp.748-755
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• 2014

In the genome annotation of Escherichia coli MG1655, the orf382 (1,149 bp) is designated as a gene encoding an alcohol dehydrogenase that may be Fe-dependent. In this study, the gene was amplified from the genome by PCR and overexpressed in Escherichia coli BL21(DE3). The recombinant $6{\times}$His-tag protein was then purified and characterized. In an enzymatic assay using different hydroxyl-containing substrates (n-butanol, $\small{L}$-threonine, ethanol, isopropanol, glucose, glycerol, $\small{L}$-serine, lactic acid, citric acid, methanol, or $\small{D}$-threonine), the enzyme showed the highest activity on $\small{L}$-threonine. Characterization of the mutant constructed using gene knockout of the orf382 also implied the function of the enzyme in the metabolism of $\small{L}$-threonine into glycine. Considering the presence of tested substrates in living E. coli cel ls and previous literature, we believed that the suitable nomenclature for the enzyme should be an $\small{L}$-threonine dehydrogenase (LTDH). When using $\small{L}$-threonine as the substrate, the enzyme exhibited the best catalytic performance at $39^{\circ}C$ and pH 9.8 with $NAD^+$ as the cofactor. The determination of the Km values towards $\small{L}$-threonine (Km = $11.29{\mu}M$), ethanol ($222.5{\mu}M$), and n-butanol ($8.02{\mu}M$) also confirmed the enzyme as an LTDH. Furthermore, the LTDH was shown to be an ion-containing protein based on inductively coupled plasma-atomic emission spectrometry with an isoelectronic point of pH 5.4. Moreover, a circular dichroism analysis revealed that the metal ion was structurally and enzymatically essential, as its deprivation remarkably changed the ${\alpha}$-helix percentage (from 12.6% to 6.3%).

• Analytical Science and Technology
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• v.13 no.3
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• pp.291-296
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• 2000

The SIMFUEL which composition is similar to PWR nuclear spent fuels was dissolved with a acid digestion bomb. An analytical conditions of ICP-AES for the direct determination of molybdenum in the uranium matrices without separation process were investigated. Based on the effect of uranium on molybdenum intensity. the most optimum wavelengths of molybdenum were found to be 202.030 and 203.844 nm. However, the method of standard additions is applied to overcome the effects of changing background caused by analyzing the sample solutions containing high concentration of uranium and the standard calibration solutions. The relative error of two methods, direct and indirect measurements with cation exchange resin separation procedures, was less than 5%. Therefore it was possible for this procedure to directly measure molybdenum in uranium matrices without separation. And this method was also applied to the determination of several percent of molybdenum in a U-Mo alloy.