• 대한방사성의약품학회지
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• 제7권2호
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• pp.147-152
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• 2021

C-11 Radiolabeled amino acid-based radiopharmaceuticals such as [¹¹C]MET for brain tumor PET imaging have limitations due to their short half-life (20 min). F-18 radiolabeled amino acid derivatives have been developed to overcome for the short half-life, one of which is [¹⁸F]FET. Brain tumor imaging using [¹⁸F]FET showed high uptake in tumor region and no non-specific uptake in inflammatory tissue, which was useful in discriminating the difference between inflammation and tumor especially. In this study, [¹⁸F]FET was synthesized using an automatic synthesis module and quality tests were carried out including enantiomeric purity analysis with reference compounds. Radiochemical yield was 50.3 ± 4.9% (n=7, decay-corrected) with molar activity of 76 ± 17 GBq/mmol. The radiochemical purity of >99%. Enantiomeric purity of [¹⁸F]FET using chiral HPLC analysis showed >99%, which was confirmed by co-injection with the L-FET and D-FET authentic standards. [¹⁸F]FET was prepared with high radiochemical yield and molar activity including no racemate mixture.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2011년도 추계학술논문요약집
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• pp.363-364
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• 2011

• 대한핵의학회지
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• 제24권1호
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• pp.101-107
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• 1990

To develop $^{131}I-labelled$ m-iodobeneylguanidine $(^{131}I-MIBG)$, various experiments such as synthesis of MIBG, establishment of labelling conditions, determination of radiochemical purity, and examination of stability were carried out. 1) m-Iodobenzylguanidine (MIBG) sulfate was synthesized with a total yield of 62.4% by the condensation of m-iodobenzylamine hydrochloride with cyanamide via MIBG bicarbonate. Its physical properties, IR, $^1H-NMR$, and elemental analysis data were nearly identical to those of literature. 2) Freeze-dried or vacuum-dried kit vials were prepared from the mixture so as to contain MIBG (2 mg), ascorbic acid (10 mg), copper (II) sulfate (0.14 mg), and tin (II) sulfate (0.5 mg) per vial. Copper ( I ) catalyzed radioiodination of MIBG was carried out using kit vials and 0.01 M $H_2SO_4$ as solvent at $100^{\circ}C$ for 30 min under nitrogen atmosphere (optimal conditions). Labelling yield was 98% and radiochemical purity was 99.5%, respectively. 3) Solid-phase radioiodination of MIBG was carried out at $155^{\circ}C$ for 30 min using the prepared vials to contain MIBG (2 mg) and ammonium sulfate (10 mg). Duplicate reactions under the same conditions showed labelling yield of 95% and radiochemical purity of 99.5%. 4) $^{131}I-MIBG$ prepared either by catalytic or by solid-phase exchange method showed radio-chemical purity of 99% even after 3 days storing at room temperature.

• 대한방사성의약품학회지
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• 제2권2호
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• pp.103-107
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• 2016

Solid phase extraction (SPE) purification method is the efficient and well-known tool for automated [$^{11}C$]acetate synthesis. A fully automated homemade module adopting the SPE method and 'pinch' valves was developed very economically with a universal interface board, a relay card and an open source programmable logic controller. The radiochemical yield of the optimized [$^{11}C$]acetate synthesis by this system was $58.8{\pm}2.1%$ (n=10, decay-corrected) from $15.5{\pm}0.19GBq$ of $[^{11}C]CO_2$ as starting activity, and total synthetic time was 15 minutes. HPLC analysis showed its high radiochemical purity as $97.4{\pm}1.1%$ without possible by-products.

• 대한방사성의약품학회지
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• 제4권2호
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• pp.90-94
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• 2018

The potential health risk from inhalational exposure of diesel exhaust particulates (DEP) has gained considerable scientific interests. However, the long-term in vivo behavior of DEP have not been clearly understood due to the difficulty of accurate analysis of these substances in a living subject. We herein demonstrate a detail protocol for the preparation of radiolabeled DEP using a radioactive-iodine-tagged pyrene analog. The purified $^{125}I$-labeled pyrene ($[^{125}I]1$) was obtained with a good radiochemical yield ($32{\pm}4%$, n=3) and high radiochemical purity (>99%) from the stannylated precursor 2. Next, the purified $[^{125}I]1$ was successfully assembled into the DEP suspension in an efficient manner. The radiolabeled DEP was highly stable in a mouse serum for 7 days without significant deiodination or dissociation of $[^{125}I]1$. These results clearly indicate that the present radiolabeling method will be useful for biodistribution study of carbonaceous particulates in vivo.

• Nuclear Engineering and Technology
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• 제54권10호
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• pp.3788-3794
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• 2022

The possibility of denuclearization of the Korean Peninsula has been continuously debated, and the initiative participation of the Republic of Korea has necessitated preemptive measures against neighboring countries. In this study, we present a proposal for formulating a site survey plan when the amount of site information provided is insufficient and the accuracy of the information is not guaranteed. Considering a case wherein "a soil sample analysis is used to determine the presence or absence of nuclear activity" in a radiochemical laboratory, which is a typical key facility for denuclearization, the optimal soil sample collection plan is designed based on international guidelines and public information. In the event of denuclearization, a scenario that is not based on the expertise of the sample collector is set, and the data quality objective (DQO) process is applied to ensure reality. Consequently, the primary sample collection points can be derived in consideration of accessibility, and the sample collection scale can be adjusted according to the cost. By applying the DQO process to ensure sample representativeness and reality, reliable and resource-efficient soil sample collection can be achieved in radiochemical laboratories and other denuclearization facilities.

• 방사성폐기물학회지
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• 제17권4호
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• pp.363-373
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• 2019

Waste characterisation associated with nuclear site decommissioning relies on radiochemical analysis of a diverse range of sample types, requiring extensive validation of analytical techniques using matrix-matched materials. The absence of relevant reference materials has hindered robust method development and validation. The paper discusses how method validation in support of nuclear waste characterisation can be achieved without using reference materials. The key stages in an analytical procedure are evaluated and a multi-stage approach is proposed with the ultimate aim of determining an operational envelope for an analytical procedure.

• Journal of Radiation Protection and Research
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• 제26권1호
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• pp.1-6
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• 2001

방사성 동위원소에 오염된 토양시료에 대하여 정확하고 신속한 U 등위원소 분석법을 개발하였고 IAEA 표준시료에 적용하여 분석법의 타당성을 검증하였다. TBP 용매추출법의 단점을 보완하기 위해서 토양시료를 질산 및 불산을 사용하여 메트릭스 성분으로부터 우라늄을 완벽하게 추출하였고 이온교환수지와 TRU Spec 수지를 이용하여 우라늄 등위원소를 악티나이드 원소로부터 순수분리하였다. 크로마토 그래피 추출법을 사용하여 토양시료에서 우라늄 등위원소 화학수율은 TBP 용매추출법의 경우보다 10% 정도 증가하였다. 크로마토 그래피 추출법을 사용한 IAEA 토양시료에 분석결과는 IAEA에서 보고된 수치와 일치하였다.

• 분석과학
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• 제8권4호
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• pp.815-820
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• 1995

Instrumental neutron and gamma activation analysis of coal and combustion products, determination of platinum content in natural samples by radiochemical gamma activation analysis and high-sensitive track method of thorium determination has been studied with the use of the MT-25 microtron.The optimal conditions for complete elemental analysis of coal and combustion products, isolation and determination of platinum and thorium are recommended.

• 대한화학회지
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• 제37권11호
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• pp.961-966
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• 1993

옛 동전(銅錢)에 존재하는 이리듐, 금과 은 등 귀금속 원소들을 정량하기 위한 연구를 수행하였다. $^{192}Ir,\;^{198}Au$ 및 $^{110m}Ag$의 방사능 세기를 계측할 때, 반감기가 긴 핵종에서 방출된 큰 감마선 에너지에 의한 간섭을 감소시키기 위하여 용매추출, 이온교환 크로마토그래피 등 방사화학 분리를 적용하였다. 그 결과 이리듐을 $10^{-11}$ g/g양까지 정량할 수 있었고, 또한 Currie의 방법으로 계산한 3종류의 검출한계, 즉 임계, 검출, 정량한계를 향상시킬 수 있었다. 이리듐의 회수율을 결정하기 위하여 담체를 첨가하여 방사화학 분리를 한 후 중성자를 제조사하였다. 5개의 동전 중의 Ir, Au 및 Ag에 대한 평균 회수율은 각각 65.3%, 98.5%, 99.5%이었다.