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  • Author or Editor: YongSam Chung x
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Abstract  

Instrumental neutron activation analysis was used to assess the concentration of the inorganic trace elements in Korean women’s blood serums. It was found that a high concentration of Na and Cl incurs an analytical interference, but the 12 elements such as Br, Ca, Cl, Co, Cr, Cs, Fe, K, Na, Rb, Se and Zn could be determined under the condition of an interference minimization. Serum samples collected from 63 women were analyzed and the concentration level and range of the elements were evaluated. NIST SRMs were analyzed simultaneously for quality control. The average values of the Na and Cl determined in the serum samples were 3,365 and 3,533 mg/l, Ca was 96.4 mg/l and K was 191 mg/l. Besides, Br, Se and Zn have a concentration level of 6.46, 0.13 and 0.98 mg/l, respectively. It was found that there is no significant difference between the present values and the reported values.

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Summary  

A prompt gamma activation analysis facility has been constructed on the ST1 horizontal beam port at the HANARO research reactor, KAERI in 2003. The detector system consists of a high-purity Ge detector surrounded by BGO/NaI(Tl) scintillators as an annulus type to reject the Compton scattered photons. Detection sensitivity for boron was obtained from the prompt gamma-ray spectra of boric acid, B(OH)3, containing 0.1-65 μg boron. The net peak for the calculation of the boron concentration was obtained by eliminating the sodium 472 keV peak, involved in the boron 478 keV peak. The biological samples used are NIST SRMs such as Peach Leaves, Apple Leaves, Tomato Leaves, Spinach Leaves, Total Diet, Typical Diet, Oyster Tissue and Corn Bran, etc. The measured values for high boron concentration showed up to a 3% of the relative, but in a low concentration below 5 ppm, present values were higher than the certified ones.

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Abstract  

Due to changes of the dietary pattern and life style, cardiovascular diseases like coronary heart disease (CHD) have been increasing in Korea. In this study, the levels of the serum minerals such as Na, Cl, K, Ca, Fe, Zn and Se for 75 patients with CHD and 25 normal persons, who were older than the age of 40, were investigated by instrumental neutron activation analysis. For analytical quality control, the reference materials. INSPQ and Seronorm, were analyzed simultaneously. The relative errors of the analytical values for the reference materials were within 10% of the certified values. The average concentrations of Na, Cl, K, Ca, Fe, Zn and Se in the serum of the male patients were 2,850±260 mg/1, 3,400±310 mg/l, 160±30 mg/l, 80.9±11.7 mg/l, 1.57±0.73 mg/l, 0.094±0.019 mg/l and 0.795±0.163 mg/l, respectively. The concentrations of Na, Cl, K, Ca, Fe, Zn and Se in the serum of the female patients were 2,890±240 mg/l, 3,430±350 mg/l, 169±27 mg/l, 81.8±13.0 mg/l, 1.26±0.44 mg/l, 0.099±0.015 mg/l and 0.769±0.105 mg/l, respectively. In a comparison between the patients and the normal group for both genders, while the levels of the elemental concentrations such as Na, Cl, K, Ca, Fe and Se were similar, the Zn concentration level of the CHD patients was significantly lower than that of the normal ones. The present study showed that the Zn concentration in the serum could be associated with CHD in Korean adults.

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Abstract  

Neutron activation analysis (NAA) has been studied to improve the accuracy and sensitivity of the analysis of trace and ultratrace metallic impurities in plastic materials. There are two main problems in the analysis of plastics by NAA. First the contamination during sample preparation, especially sample crushing procedure is very serious for ultratrace analysis. Another problem is the destruction of the sample capsule due to the pressure build-up by the gases formed during neutron irradiation. A simple preparation technique of the sample crushing method using liquid nitrogen and reducing the capsule pressure by a pin hole was developed to solve the above problems. Two different irradiation and seven cooling conditions were also investigated to optimize the experimental conditions. A SRM from NIST (1632b coal) has been used to investigate the accuracy of the analysis. More than thirty elements could be analyzed in the range of sub-ppb to percent. Samples analyzed in this work were polyethylene and polypropylene which were made by different manufacturing procedure, and pigments. Two kinds of plastic products used for food and drug containers were also analyzed. It was found that NAA could be a powerful technique for the analysis of metallic impurities in plastics even though their concentrations were at ultratrace levels.

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Abstract  

The k 0-standardization method (k 0-NAA) is known as one of the most remarkable progresses of the NAA with its many advantages. For the application of k 0-NAA method at the NAA #1 irradiation position where the neutrons are well thermalized in the HANARO research reactor, KAERI, Korea, the determination of the reactor neutron spectrum parameters such as α and f have been carried out. The measured values of α and f using the “Cd-ratio” triple monitor method were 0.127±0.022 and 1010±70, respectively. To evaluate the applicability of k 0-NAA in our analytical system, the analysis of three kinds of SRMs was executed. The analytical results showed that the relative error of most of the elements was less than 10% and the U-scores were within 2. It is turned out that the procedure of the k 0-NAA in the HANARO research reactor is available for a practical application in the environmental fields.

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Abstract  

To enhance the applicability of the nuclear analytical technique in the field of industry and the environment, the inorganic elemental content of the bottom ash from a municipal solid waste incinerator was determined by instrumental neutron activation analysis. Bottom ash samples were monthly collected from an incinerator located at a metropolitan city in Korea, strained through a 5 mm sieve, dried by an oven and pulverized by an agate mortar. The samples were irradiated at the NAA #1 irradiation hole (thermal neutron flux: 2.92·1013 n·cm−2·s−1) in the HANARO research reactor of the Korea Atomic Energy Research Institute and the irradiated samples were measured by a HP Ge gamma-ray spectrometer. Thirty-three elements including As, Cr, Cu, Fe, Mn, Sb and Zn were analyzed by an absolute method. The quality control was conducted by a simultaneous analysis with NIST standard reference materials. The average concentrations of the major elements such as Ca, Fe, Al, Na, Mg, K and Ti measured in the sample were 19.9%, 4.85%, 3.79%, 2.11%, 1.84%, 1.22% and 1.02%, respectively. In addition, the concentrations of the hazardous metals like Zn, Cu, Cr, Sb and As were 0.77%, 0.31%, 729 mg·kg−1, 116 mg·kg−1 and 22.2 mg·kg−1, respectively.

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Summary  

As part of an air pollution monitoring study, airborne particulate matter (PM2/PM10-2) samples were collected from 2000 to 2003 at two sampling sites in an urban region, Daejeon, the middle of Korea. Mass concentrations of both fine and coarse fractions and that of the black carbon in the fine particles were measured using the Gent stacked filter unit sampler and the smoke stain reflectometer, respectively. In the collected samples the concentrations of 24 elements were analyzed using instrumental neutron activation analysis. Monitored data were investigated for their temporal trends under different environmental conditions and their seasonal correlation patterns. Crustal enrichment factors were also estimated to establish the contribution between anthropogenic and crustal origin. Patterns for airborne particle matter (APM) and elemental concentrations, seasonal variation of some marker elements were investigated. The results can be applied for the investigation of further air pollution sources and for the evaluation of air quality.

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Summary  

For the identification of air pollution sources, about 500 airborne particulate matter (PM2.5and PM10) samples were collected by using a Gent air sampler and a polycarbonate filter in an urban region in the middle of Korea from 2000 to 2003. The concentrations of 25 elements in the samples were measured by using instrumental neutron activation analysis (INAA). Receptor modeling was performed on the air monitoring data by using the positive matrix factorization (PMF2) method. According to this analysis, the existence of 6 to 10PMF factors, such as metal-alloy, oil combustion, diesel exhaust, coal combustion, gasoline exhaust, incinerator, Cu-smelter, biomass burning, sea-salt, and soil dust were identified.

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Abstract  

Instrumental neutron activation analysis was used for the analysis of 25 trace elements in airborne particulate matter (PM) for air pollution monitoring. For the collection of air samples, the Gent stacked filter unit low volume sampler and two types of Nuclepore polycarbonate filters were employed. Samples were collected at selected sampling dates in suburban and industrial regions of Daejon city in the Republic of Korea. Mass concentrations and black carbon of PM were measured, and enrichment factors were calculated. The results were used to describe the emission sources and their correlation patterns.

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Abstract  

For air pollution monitoring, about 1300 airborne particulate matter samples were collected by using a low volume air sampler and a polycarbonate filter at two sampling sites in an urban region, Daejeon, the middle of Korea from 2003 to 2006. Mass concentrations of the black carbon were measured using a smoke stain reflectometer. The concentrations of 24 elements in the collected samples were analyzed by using instrumental neutron activation analysis, and its temporal trends and enrichment factors were investigated under different environmental conditions. Analytical control was carried out by using certified reference materials.

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