• Nuclear Engineering and Technology
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• 제12권1호
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• pp.29-38
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• 1980

중성자 방사화분석법으로 알루미늄중 28개의 미량원소들의 분석을 위하여 방사화학적 분리방법을 개발하였다. 이 분리법은 이온 교환수지와 무기질 이온 교환체를 사용한 군분리에 기초를 둔 것으로서 이온교환통은 유리관을 사용하였으며 용매는 불산용액을 제외한 무기산용액 혹은 유기용매와 혼합된 무기산 용액을 사용하였다. 함량은 분리된 카 원소들의 방사능을 $3"\times3"\;Nal(TI)$ 검출기로 감마선 스펙트럼을 구한 다음 단일비교 체법으로 결정하였다.

• Nuclear Engineering and Technology
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• 제13권4호
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• pp.237-244
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• 1981

이산화우라늄중의 미량불순물원소들의 중성자 방사화분석을 위하여 이들 원소들의 사전농축에 음이온교환수지를 사용하였다. 황산에 녹인 우라늄 시료용액의 산도를 pH 2.7에 맞춘다음 음이온교환수지통에 얹었다. 이 음이온교환수지통으로 부터 미량분순물 원소만을 정량적으로 회수할 수 있었다. 이 사전농축법과 알미늄중 미량불순물 원소의 정량을 위하여 개발한 방사화학적인 분리법을 이용하므로서 원자로급 이산화우라늄 중의 21개 미량불순물을 정량할 수 있었다.

• 대한화학회지
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• 제5권1호
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• pp.26-28
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• 1961

Microgram quantities of thallirum in meteorites, rocks, minerals, alloys and biological samples have been analyzed by rapid neutron activation analysis. A l0-minute radiochemical separation procedure coupled with a gas-flow proportional detector for 4.2-minute half life measurement and a gamma or beta scintillation detector placed in close proximity to the sample permitted detection of the 4.2-min Tl206. Samples were irradiated for 10-minutes at a thermal neutron flux of approximately $0.95{\times}10^{11}$ neutron-$cm^{-2}-sec^{-1}.$ The low limits of detection was about $10^{-7}$ gm of thallium.

• Environmental Analysis Health and Toxicology
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• 제1권1호
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• pp.77-80
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• 1986

$N^{G}$ -Mono［$^{14}$ C-Methyl］-L-arginine을 방사선화학적 방법으로 mono ［$^{14}$ C］-Methylamine 으로부터 합성한후 양이온 교환수지에 흡착시킨 다음 암모니아수로 용출시켜 정제하였으며 flavianic acid를 사용하여 결정상태로 얻었다. 한편 flavianate와 음이온 교환수지 를 함께 실온 이하의 온도에서 교반혼합함으로서 유리 상태의 amino acid를 쉽게 만들수 있으며 박층크로마토그라피, 박층전기영동 및 섬광분광분석법으로 순도를 조사하였다.

• Journal of Radiation Protection and Research
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• 제40권2호
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• pp.101-109
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• 2015

대기 중에 존재하는 우라늄 동위원소 분석을 위해서 일반적으로 알파분광분석법(alpha spectrometry)이 사용되고 있으며, 정확한 분석을 위해서는 정밀한 방사화학 전처리가 요구된다. 보편적인 방사화학 전처리 방법으로는 회화법(ashing method) 및 알칼리 용융법(alkali fusion method)가 있다. 그러나 회화법의 경우 전처리 시간이 길어 빠른 분석이 어렵다는 단점이 있으며, 이와 달리 알칼리 용융법은 단시간 내에 전처리가 가능하다는 장점은 있으나 보편적으로 전처리 장비의 무게가 무겁고 분석 소요 비용 역시 상당히 높다는 단점이 있다. 이러한 단점들은 신속한 분석 결과가 요구되는 방사능 사고 분석 또는 IAEA 안전조치 물자재고 검사(Physical Inventory Verification, PIV) 수행시, 효율성을 저하시키는 원인이 된다. 이에 본 연구에서는 간편하면서도 주어진 짧은 시간 내에 공기 중 우라늄 동위원소 분석을 완료하는 것을 목적으로, 초음파 세척법(ultrasonic cleaning method)을 이용한 새로운 방사화학 전처리 방법을 개발하였다. 또한 초음파 세척법의 효율성 분석을 위해 전처리 소요시간, 편의성, 소요비용, 우라늄 동위원소 회수율의 측면에서 기존의 방법들과 비교 분석하였다. 동일 조건의 공기 포집시료에 대해 비교실험을 수행한 결과, 본 연구에서 개발한 초음파 세척법을 활용한 공정은 상대적으로 전처리 시간도 짧고, 이동이 간편하며, 저가이며, 단순함에도 불구하고 기존 방식과 비교하여 유사한 회수율을 보였다.

• Journal of Pharmaceutical Investigation
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• 제4권4호
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• pp.17-25
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• 1974

1. Neutron acivation analysis of arsenic contained in Korean human liver was studied in the view point of forensic chemistry, using 12 corpses. A sample of 1g was irradiated for 30 mins. in a neutron flux of $1.2{\times}10^{12}n/cm^2/sec$, followed by nitric-sulfuric acid digestion and then by Gutzeit separation. Radio activity was detected by it's scintillation counter. The arsenic content in the liver was found to be $0.01{\mu}g/g$ to $0.15{\mu}g/g$. 2. A rapid and convenient method for the radiochemical determination of minerals by neutron activation analysis was established. After neutron irradiation to the standard soln. of Cu and Mn in pneumatic tube (neutron flux : $1.2{\times}10^{12}n/cm^2/sec$), Cu and Mn were determined by estimating the ratio of the widths under energy peak area in ${\gamma}-ray-spectrogram$. When the standard soln. of Mn and Cu is irradiated for 15 mins. to 18 hrs., recovery test shows that the relative errors are 5.1% and 4.5% for copper and manganese, respectively.

• 방사성폐기물학회지
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• 제19권3호
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• pp.367-386
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• 2021

The overestimation and underestimation of the radioactivity concentration of difficult-to-measure radionuclides can occur during the implementation of the scaling factor (SF) method because of the uncertainties associated with sampling, radiochemical analysis, and application of SFs. Strict regulations ensure that the SF method as an indirect method does not underestimate the radioactivity of nuclear wastes; however, there are no clear regulatory guidelines regarding the overestimation. This has been leading to the misuse of the SF methodology by stakeholders such as waste disposal licensees and regulatory bodies. Previous studies have reported instances of overestimation in statistical implementation of the SF methodology. The analysis of the two most popular linear models of the SF methodology showed that severe overestimation may occur and radioactivity concentration data must be dealt with care. Since one major source of overestimation is the use of minimum detectable activity (MDA) values as true activity values, a comparative study of instrumental techniques that could reduce the MDAs was also conducted. Thermal ionization mass spectrometry was recommended as a suitable candidate for the trace level analysis of long-lived beta-emitters such as iodine-129. Additionally, the current status of the United States and Korea was reviewed from the perspective of overestimation.

• 대한핵의학회지
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• 제23권1호
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• pp.71-83
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• 1989

For the development of $^{99m}Tc-labelled$ antimony sulfide colloid and hydroxyethyl starch, various experiments such as preparation of colloid, control of the distribution of particle size, establishment of labelling conditions, determination of labelling yield and radiochemical purity, examination of stability, and organ imagings of rabbits etc. were carried out. 1) Antimony sulfide colloid was readily prepared by the reaction of aqueous solution of antimony potassium tartrate with hydrogen sulfide generated by treating ferrous sulfide with dilute sulfuric acid. The colloid could be stabilized by adding small amount of polyvinylpyrrolidone. 2) Electron microscopy analysis exhibited the distribution of colloid size in the range of $1\sim15nm$ with a major portion of 9 m. The colloid solution was sterilized by membrane filtration $(0.2{\mu}m)$ and then stored at $4^{\circ}C$. This sterilized colloid was so stable that it was usable at least for one year. 3) The antimony sulfide colloid was labelled by adding sodium $pertechnetate-^{99m}Tc$ solution to the reaction vial, followed by adding hydrochloric acid and then boiled for 30 min. The optimal pH of the reaction mixture was found to be in the range of $1.3\sim1.4$. Instant thin layer chromatography (ITLC) analysis showed high labelling yield of above 99.5%. This labelled colloid maintained high radio-chemical purity of above 99% until 10 hours after labelling. 4) Animal studies showed high uptake of $^{99m}Tc-Sb_2S_3$ colloid at lymph vessels and nodes indicating a suitable agent for lymphoscintigraphy. Satisfactory results were also abtained in other clinical studies. 5) Hydroxyethyl starch (HES $0.6\sim1.0%$) was labelled with $Na^{99m}TcO_4$ in the presence of $SnCl_2$ with high labelling yield of above 99.5%. The optimal pH of the reaction mixture was in the range of $1.8\sim2.0$. $^{99m}Tc-HES$ maintained high radiochemical purity of above 99% until 10 hours after labelling. 6) Animal studies showed that $^{99m}Tc-HES$ migrated more rapidly from the injection sites into the lymph vessels than $^{99m}Tc-Sb_2S_3$ colloid while less amount of the former was uptaken at lymph nodes than that of the latter. Similar phenomenon was also observed in other clinical studies. As a result, $^{99m}Tc-Sb_2S_3$ colloid was found to be more effective lymphoscintigraphic agent than $^{99m}Tc-HES$.

• 한국의류학회지
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• 제24권3호
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• pp.422-428
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• 2000

At present, analytical methods available for determining the amount of cationic surfactants(DSDMAC) on the fabrics are spectrophotometric method based on formation and extraction of the colored ion pair with anionic dye, radiochemical analysis and HPLC analysis. This study presents new analytical methods based on the formation of cationic surfactant(DSDMAC)-disulfine blue complex on the cotton fabric. Test methods for determining the amount of DSDMAC-disulfine blue complex on the cotton fabrics are measuring the reflectance of the colored fabric and the absorbance of the methanol solution of DSDMAC-disulfine blue complex extracted from dyed cotton fabric. Linear relationships between the K/S value of the fabric treated with DSDMAC followed by disulfine blue and the amount of DSDMAC sorbed by cotton fabric were obtained. Thus, the amount of DSDMAC sorbed by cotton fabric can be determined by K/S value of the fabric. DSDMAC-disulfine blue complex on the cotton fabric was extracted with methanol. The amount of DSDMAC sorbed by cotton fabric was estimated by measuring the absorbance of the methanol solution extracted from dyed cotton fabric.

• 방사성폐기물학회지
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• 제18권4호
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• pp.517-536
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• 2020

The radionuclide inventory in radioactive waste from nuclear power plants should be determined to secure the safety of final repositories. As an alternative to time-consuming, labor-intensive, and destructive radiochemical analysis, the indirect scaling factor (SF) method has been used to determine the concentrations of difficult-to-measure radionuclides. Despite its long history, the original SF methodology remains almost unchanged and now needs to be improved for advanced SF implementation. Intense public attention and interest have been strongly directed to the reliability of the procedures and data regarding repository safety since the first operation of the low- and intermediate-level radioactive waste disposal facility in Gyeongju, Korea. In this review, statistical methodologies for SF implementation are described and evaluated to achieve reasonable and advanced decision-making. The first part of this review begins with an overview of the current status of the scaling factor method and global experiences, including some specific statistical issues associated with SF implementation. In addition, this review aims to extend the applicability of SF to the characterization of large quantities of waste from the decommissioning of nuclear facilities.