• 한국콘텐츠학회논문지
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• 제9권11호
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• pp.240-246
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• 2009

본 연구의 목적은 방사성 의약품의 정도관리 실험 중 방사선 및 의약품측면에서의 방사핵종 순도, 화학적 순도, 방사화학적 순도의 세 가지로 진행하였다. 또한 방사성 의약품을 표지 후 시간에 따른 표지 효율을 관찰함으로써 실제 임상에서 표지 후 어느 정도의 시간이 경과해도 사용이 가능한지 실험해 보았다. 그 결과 현재 임상에서 사용되고 있는 방사성의약품의 방사성핵종 순도와 화학적 순도는 양호한 편이었으나, 방사화학적 순도는 표지방법과 표지 시간에 따라 약간의 차이를 띄고 있었다. 방사성 의약품은 시술자의 손을 거쳐 표지되기 때문에 표지과정에 주의를 하여 정도관리에 임한다면 보다 효율적인 검사가 가능할 것으로 보여 진다.

• 분석과학
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• 제35권6호
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• pp.249-255
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• 2022

본 연구에서는 기체 크로마토그래피-불꽃이온화검출기(GC-FID)를 이용한 고순도 질소의 새로운 순도분석법을 개발하였다. 고순도 질소에 존재할 수 있는 불순물인 일산화탄소(CO), 이산화탄소(CO₂), 및 메탄(CH₄)에 대한 3 µmol/mol 수준의 인증표준물질(Certified reference material, CRM)을 중량법을 이용하여 제조하였고, 이를 순도분석에 활용하였다. 개발된 순도분석법에서는 운반가스로 초고순도 질소와 순도분석 대상 질소를 사용하여, 제조된 인증표준물질의 기체 크로마토그래피에서 얻어지는 크로마토그램의 면적 값 차이를 비교함으로써 순도분석 대상 질소의 불순물을 정량 분석하였다. 순도분석 대상 질소로는 액체질소 및 제조사가 각기 다른 3곳의 고순도 질소를 사용하였다. 또한, 개발된 순도분석법의 유효성을 평가하기 위하여 순도분석 대상 질소 내 불순물의 물질량 분율을 기존 순도분석법과 비교하였다. 두 가지 순도분석법을 이용하였을 때 대상 질소 내 불순물의 물질량 분율이 불확도 (k = 2) 내에서 서로 일치함을 확인함으로써, 개발된 순도분석법이 유효함을 확인하였다.

• 대한금속재료학회지
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• 제50권12호
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• pp.907-911
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• 2012

High purity silicon can be obtained from Al-Si alloys by a combination of solvent refining and centrifugation. Silicon purification by crystallization of silicon from an Al-Si alloy melt was carried out using 2N and 4N purity aluminum and 2N purity silicon as raw materials. The effect of the purity of raw materials on the final silicon ingot purity by centrifugation was investigated for an Al-50 wt% Si alloy. Alloys were melted using an electrical resistance furnace, and then poured into a centrifuging apparatus. A silicon lump like foam was obtained after centrifugation and was leached by an acid in order to get pure silicon flakes. Then silicon flakes were melted to make a silicon ingot using an induction furnace. The purities of the silicon flakes and silicon ingot were enhanced significantly compared to those of the raw materials of silicon and aluminum. The silicon ingot made of 4N aluminum and 2N silicon showed the lowest impurities.

• Journal of Microbiology and Biotechnology
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• 제20권11호
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• pp.1534-1538
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• 2010

Fed-batch cultures of Hansenula polymorpha were studied to develop an efficient biosystem to produce recombinant human serum albumin (HSA). To comply with this purpose, we used a high-purity oxygen-supplying strategy to increase the viable cell density in a bioreactor and enhance the production of target protein. A mutant strain, H. polymorpha GOT7, was utilized in this study as a host strain in both 5-l and 30-l scale fermentors. To supply high-purity oxygen into a bioreactor, nearly 100% high-purity oxygen from a commercial bomb or higher than 93% oxygen available in situ from a pressure swing adsorption (PSA) oxygen generator was employed. Under the optimal fermentation of H. polymorpha with highpurity oxygen, the final cell densities and produced HSA concentrations were 24.6 g/l and 5.1 g/l in the 5-l fermentor, and 24.8 g/l and 4.5 g/l in the 30-l fermentor, respectively. These were about 2-10 times higher than those obtained in air-based fed-batch fermentations. The discrepancies between the 5-l and 30-l fermentors with air supply were presumably due to the higher contribution of surface aeration over submerged aeration in the 5-l fermentor. This study, therefore, proved the positive effect of high-purity oxygen in enhancing viable cell density as well as target recombinant protein production in microbial fermentations.

• 분석과학
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• 제32권6호
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• pp.225-232
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• 2019

Traceability establishment in chemical measurements is a like a linkage established through an unbroken chain from the measured results to the international system (SI) of units. The primary process for traceability establishment is the purity assignment of a target material to be measured. In this study, we studied the purity assignment of 17α-hydroxyprogesterone (17-OHP). The presence of 17-OHP is indicative of congenital adrenal hyperplasia (CAH) and it builds up due to the deficiency of 21-hydroxylase and 11β-hydroxylase enzyme in the human blood. The purity assignment of 17-OHP was performed by the mass balance method, in which the impurities are categorized into four classes: total related structural impurities, water, residual organic solvents, and nonvolatiles/inorganics. The total related structural impurities were characterized by HPLC-UV; water content was determined by Karl-Fisher coulometer; and the total residual solvents and nonvolatiles/inorganics were determined by TGA. The purity of 17-OHP from a commercial manufacturer was calculated as 993.30 mg/g, and the expanded uncertainty was 0.58 mg/g. The proposed method was validated by uncertainty evaluation and comparing with the actual value of purity.

• 대한화학회지
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• 제55권4호
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• pp.566-569
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• 2011

• 분석과학
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• 제30권5호
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• pp.226-233
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• 2017

In general, quantitative chemical analysis in various areas including food, the environment, in vitro diagnostics, etc., requires traceability in order to increase the reliability of the measurements. Measurement traceability is a property of an unbroken chain of comparisons relating an instrument's measurements to SI units. Purity analysis is the first process for establishing traceability to SI units in chemical measurements. The purpose of this study is to develop and validate a method of purity assignment for establishing the traceability of $17{\beta}$-estradiol measurements in an in vitro diagnostics field. The establishment of this method is very important as it can be applied to the development of CRM and to the analysis of the purity of other hormones. The method of assignment of the purity of $17{\beta}$-estradiol was developed using the mass balance method and was validated through participation in an International comparison. In the mass balance method, impurities are categorized into four classes as follows: total related structure impurities, water, residual organic solvents, and nonvolatiles/inorganics. In this study, total related structure impurities were characterized by a gas chromatography-flame ionization detector (GC-FID) and a high-performance liquid chromatography-ultraviolet (HPLC-UV) detector, water content was determined by a Karl-Fisher coulometer, and total residual solvents and nonvolatiles/inorganics were checked simultaneously by thermogravimetric analysis (TGA). The purity of the $17{\beta}$-estradiol was 985.6 mg/g and the expanded uncertainty was 2.1 mg/g at 95% confidence. The developed method can be applied to the development of certified reference materials, which play a critical role in traceability.

• 한국응용과학기술학회지
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• 제24권2호
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• pp.140-148
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• 2007

As an additional high purification method of p-dioxanone monomer for a high molecular weight polymer, the sweating operation of crystalline layer obtained by layered melt crystallization from p-dioxanone-diethylene glycol system was studied. Purity and yield of p-dioxanone crystal depended mainly on the sweating temperature and sweating time. Increasing sweating time and sweating temperature, the purity of p-dioxanone crystal increase, whereas the yield of that decrease, respectively. Through the optimization of sweating operation, p-dioxanone crystal can be upgraded to very high purity over 99.9 % suited to monomer for polymerization.

• Bulletin of the Korean Chemical Society
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• 제30권8호
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• pp.1821-1826
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• 2009

Liquid crystal display (LCD) devices contain a colour filter which can visualise colour images by transmitting or absorbing light. Colour properties of LCD mainly depend on colour materials such as pigments and polymeric binders. In this paper, colour properties were studied to improve colour quality of LCD. Generally, the colour properties can be classified into three categories which are colour purity, brightness and contrast ratio. For this study, photo resists were prepared by treatment of pigments and synthesis of polymeric binder. The treated pigments were dispersed and formulated with additives for preparing a photo resist that could be used for manufacturing colour filters. As a result of what we studied, type, mixture ratio and concentration of pigments were very important to improve colour purity of LCD device.

• KSBB Journal
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• 제29권4호
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• pp.250-262
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• 2014

A simulation study for finding purity changes of extract and raffinate as well as the best purity of (S)-ketoprofen in simulated moving bed (SMB) was performed with changing parameters of $m_2$ and $m_3$ from triangle theory. Aspen simulator allowed separation process simulation of (R)- and (S)-ketoprofen in SMB and compared 4-bed SMB and 8-bed SMB based on the same Henry constant and mass transfer coefficient. The 4-bed SMB consisted of 4 columns (200 mm of length, 10 mm of diameter) and the 8-bed SMB constructed by 8 columns (100 mm of length, 10 mm of diameter), and therefore total column length was made the same as 800 mm. Considering purities of both (R)-and (S)-ketoprofen, both 4-bed SMB and 8-bed SMB had the best purity when $m_2$ and $m_3$ were on 12.0 and 13.0 in the center of triangle. Taking only (S)-ketoprofen into account, 4-bed SMB as well as 8-bed SMB had the best purity when $m_2$ and $m_3$ were on 10.9 and 12.6 in the left outside triangle, and their purities were 93.3 % for 4-bed SMB and 96.9 % for 8-bed SMB.