• Korean Journal of Environmental Agriculture
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• v.37 no.4
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• pp.291-301
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• 2018

BACKGROUND: Rice is one of the main sources for inorganic arsenic among the consumed crops in the world population's diet. Arsenic is classified into Group 1 as it is carcinogenic for humans, according to the IARC. This study was carried out to assess dietary exposure risk of inorganic arsenic in husked rice and polished rice to the Korean population health. METHODS AND RESULTS: Total arsenic was determined using microwave device and ICP-MS. Inorganic arsenic was determined by ICP-MS coupled with HPLC system. The HPLC-ICP-MS analysis was optimized based on the limit of detection, limit of quantitation, and recovery ratio to be $0.73-1.24{\mu}g/kg$, $2.41-4.09{\mu}g/kg$, and 96.5-98.9%, respectively. The inorganic arsenic concentrations of daily exposure (included in body weight) were $4.97{\times}10^{-3}$ (${\geq}20$ years old) $-1.36{\times}10^{-2}$ (${\leq}2$ years old) ${\mu}g/kg\;b.w./day$ (PTWI 0.23-0.63%) by the husked rice, and $1.39{\times}10^{-1}$ (${\geq}20$ years old) $-3.21{\times}10^{-1}$ (${\leq}2$ years old) ${\mu}g/kg\;b.w./day$ (PTWI 6.47-15.00%) by the polished rice. CONCLUSION: The levels of overall exposure to total and inorganic arsenic by the husked and polished rice were far lower than the recommended levels of The Joint FAO/WHO Expert Committee on Food Additives (JECFA), indicating of little possibility of risk.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.7 no.1
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• pp.25-31
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• 2009

An analytical method of $^{99}Tc$ concentration in soil was set up and discussed considering the $^{99}Tc$ concentration in Korean soil measured with its analytical method. A selective TEVA resin was used to separate and purify the $^{99}Tc$ in the soil sample. $^{99m}Tc$ from a commercial $^{99}Mo/^{99m}Tc$ generator was used as a yield tracer for the chemical separation of $^{99}Tc$ and its problem when using $^{99m}Tc$ as a tracer was discussed. The chemical recovery yield of $^{99}Tc$ was above 70%. The optimum conditions of inductively coupled plasma mass spectrometry system(ICP-MS) were set up to determine the $^{99}Tc$ after the separation process. The minimum detectable activity(MDA) was 15 mBq/kg-dry in this analytical procedure. The $^{99}Tc$ concentration in soils of Jeju and Kori were measured in the rage of 33.73-89.16 mBq/kg-dry. Those values were less than those reported in other countries and seemed to be originated from atmospheric fallout.

• Journal of the Korean Chemical Society
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• v.34 no.1
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• pp.69-75
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• 1990

An ion-association chromatography was applied for the separation and determination of individual rare earth elements (REE) contained in mineral monazite. Prior to the determination, the group separation of REE was achieved by a cation exchange column of Dowex 5OW-X8 resin. The quantitative recovery of REE by the resin column, free from coexisting elements in monazite, was confirmed with radioactive tracers as well as with ICP-MS. Individual REE at ppm level was separated on reversed-phase column ($\mu$-Bondapak $C_{18}$) using gradient elution from 0.05 to 0.3 M $\alpha$-hydroxyisobutyric acid at pH 4.6. The individual REE was detected at 546 nm following post-column reaction with PAR (4-(2-pyridylazo)-resorcinol monosodium salt).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.11
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• pp.6015-6022
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• 2013

It has been known that there are large amount of nitric acid and valuable metals, copper in the plating waste solution of automobile wheel. As nitric acid and valuable metals are high price and toxic, they should be recovered for economics and environment. Plating waste was extracted with TBP diluted with kerosene. The concentration of nitric acid in aqueous phase was analyzed by titration method by NaOH solution (0.1~1.0N) and the amount of metals by ICP-MS and ICP-AES. The concentration of copper in plating waste were 76,850 mg/L. The concentration of nitric acid in plating waste was 1.02 M. After three step extraction was performed with 50% TBP, each organic phase was stripped three times with distilled water to obtain 48.1% of nitric acid. Purity of final nitric acid was over 99.9% by ICP analysis. After recovery of nitric acid, copper was extracted with various solvent extractors like PC 88A, D2EPHA, LIX 84 and ISE 106. Among these extractors, 92% of copper was recovered by ISE 106 after 1st extraction and 30% $H_2SO_4$ stripping. Copper ion was reduced with $N_2H_4$ to make metal powders, respectively.

• Analytical Science and Technology
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• v.11 no.6
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• pp.485-494
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• 1998

Ternary and quaternary alloys composed of Mo-Ru-Rh-Pd were prepared and their crystal structure and quantitative chemical compositions were analysed by XRD, WDX, EDX and ICP/AES. The results of X-ray diffraction studies showed that the alloys were crystallized in hexagonal close packing, well known as ${\varepsilon}$-phase with $P6_3/mmc$ of space group. The optimum accelerating voltage for Zr~Cd(40~48) analyzed by EPMA using PET crystal was found to be 15 kV and the linear regression coefficient(R) of atomic number and X-ray intensity was approximately 0.998 without Tc standard specimen. The WDX results of alloys of Mo and Pd by linear regression equations were detected to be 0.1% lower compared to WDX analysis results using standard specimen, while Ru, Rh were detected 3% higher. These alloys were completely dissolved in mixed acid of 12.5 mL HCl and 1 mL $HNO_3$, at $220^{\circ}C$ for 22 hours using autoclave with PTFE vessel. There was no reprecipitating phenomnon when diluted 100 times with 1N-HCl. The results of ICP/AES analysis deviated less than 4% comparing with those of normal WDX analysis.

• Applied Chemistry for Engineering
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• v.26 no.3
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• pp.372-376
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• 2015

6-MQCC (Cr(VI)-6-methylquinoline) complex was synthesized by the reaction of 6-methylquinoline with chromium(VI) trioxide in 6 M HCl. The structure was characterized using IR (Infrared Spectroscopy) and ICP (Inductively Coupled Plasma) analysis. The oxidation of benzyl alcohol using 6-MQCC in various solvents showed that the reactivity increased with the increase of the dielectric constant, in descending order of DMF > acetone > chloroform > cyclohexene. In the presence of DMF solvent with acidic catalyst such as sulfuric acid ($H_2SO_4$), 6-MQCC oxidized benzyl alcohol (H) and its derivatives ($p-OCH_3$, $m-CH_3$, $m-OCH_3$, m-Cl, $m-NO_2$) were effectively oxidized. Electron-donating substituents accelerated the reaction rate, whereas electron acceptor groups retarded the reaction rate. The Hammett reaction constant (${\rho}$) was -0.69 (308 K). The observed experimental data was used to rationalize the fact that the hydride ion transfer occurred at the rate-determining step.

• Applied Chemistry for Engineering
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• v.27 no.1
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• pp.110-114
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• 2016

Cr(VI)-pyrazine complex (PZCC) was synthesized by the reaction of pyrazine with chromium (VI) trioxide in 6 M HCl. The structure was characterized using IR spectroscopy and inductively coupled plasma (ICP). The oxidation of benzyl alcohol using PZCC in various solvents showed that the reactivity increased with the increase of the dielectric constant, in the order: N,N'-dimethylform-amide > acetone > chloroform > cyclohexene. In the presence of N,N'-dimethylformamide solvent with an acidic catalyst such as sulfuric acid ($H_2SO_4$ solution), PZCC oxidized benzyl alcohol (H) and its derivatives ($p-OCH_3$, $m-CH_3$, $m-OCH_3$, m-Cl, $m-NO_2$). Electron-donating substituents accelerated the reaction rate, whereas electron acceptor groups retarded the reaction rate. Hammett reaction constant (${\rho}$) was -0.70 (308 K). The observed experimental data were used to rationalize the hydride ion transfer in the rate-determining step.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.8
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• pp.772-778
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• 2005

In this paper, we designed the cylindrical type light source that had a electromagnetic principle of inductively coupled plasma, and measured its electrical-optical properties. Using the principle of transformer, electrically equivalent circuit of cylindrical type light source was analyzed. According to the parameters of electromagnetic induction which were diameter of coil with $0.3\~1.2\;mm{\Phi}$, number of turns with $4\~12$ turns, distance with $40\~120$ mm and RF power with $10\~150$ W, the electrical and optical properties were measured. When diameter of coil was $0.3\;mm{\Phi}$, number of turns was 8 turns and distance was 40 mm, the highest brightness of 29,730 $cd/m^2$ was shown with RF power 150 W. The relationship between electromagnetic induction and plasma discharges was shown by mode transition from E-mode to H-mode.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.185-186
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• 2006

Image Guided Surgery(IGS) system has been developed to provide exquisite and objective information to surgeons for surgical operation process. It is necessary that registration technique is important to match between 3D image model reconstructed from image modalities and the object operated by surgeon. Majority techniques of registration in IGS system have been used by recognizing fiducial markers placed on the object. However, this method has been criticized due to its invasive protocol inserting fiducial markers in patient's bone. Therefore, shape-based registration technique using geometric characteristics of the object has been invested to improve the limitation of IGS system. During Total Knee Replacement(TKR) operation, it is challenge to register with high accuracy by using shape-based registration because the area to acquire sample data from knee is limited. We have developed region-based 3D registration technique based on anatomical landmarks on the object and this registration algorithm was evaluated in femur model. It was found that region-based algorithm can improve the accuracy in 3D registration. We expect that this technique can efficiently improve the IGS system.

• Journal of the Korean institute of surface engineering
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• v.38 no.2
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• pp.79-82
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• 2005

This study investigated the effect of nitriding on the hardness and adhesion properties of $TiB_2$ coatings. Inductively coupled plasma (ICP) was used for both nitriding and deposition. By applying ICP, H13 steel was nitrided at a high rate of $50\;{\mu}m/hr$. After nitriding, a Fe4N compound layer or a diffusion layer was formed according to the hydrogen/nitrogen ratio. Both layers could improve the load-bearing capacity of the substrate by increasing the substrate hardness. The adhesion of the $TiB_2$ coatings increased to $\~30N$ after nitriding, but the hardness of the coating was lowered to 20-30 GPa. However, the adhesion of the $TiB_2$ coatings with a high hardness (>60 GPa) could not be improved substantially by nitriding due to the large difference in hardness between the coating and the substrate. The grain size of the $TiB_2$ coating was larger on the nitrided substrates, resulting in a decrease in the hardness of the coating.