• Title/Summary/Keyword: Chemical Purity

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Quality Control of Radiopharmaceutical (진단용 방사성 의약품의 정도관리)

  • An, Sung-Min;Hong, Tae-Kee;Ham, Jun-Cheol;Kim, Sung-Chul
    • The Journal of the Korea Contents Association
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    • v.9 no.11
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    • pp.240-246
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    • 2009
  • Quality control test in this field of study were carried out in 3 categories, radionuclidic purity, chemical purity and radiochemical purity. Also, indication efficiency was tested every 3 hours changed after binding the radiopharmaceutical to see how long the medicine is available for usage after indicating. The result showed that currently used radiopharmaceutical have good radionuclidic purity and chemical purity. However, radiochemical purity indication showed small differences depending on indication method and indication period. Radiopharmaceutical are indicated by treatment providers, so they need to pay more attention to the indication process and quality control to provide more efficient treatment.

Development of analysis method for high purity nitrogen using GC-FID/Methanizer (GC-FID/Methanizer를 이용한 고순도 질소의 순도분석법 개발)

  • Jei, You;Jin Bok, Lee;Jin Seog, Kim;Woonjung, Kim;Kiryong, Hong
    • Analytical Science and Technology
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    • v.35 no.6
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    • pp.249-255
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    • 2022
  • In this study, a new method for the analysis of high-purity nitrogen was developed. A gas chromatography-flame ionization detector (GC-FID) was used for purity analysis. Certified reference materials (CRMs) at a level of 3 µmol/mol of carbon monoxide (CO), carbon dioxide (CO2), and methane (CH4), which may exist in high-purity nitrogen, were prepared using the gravimetric method, and these CRMs were used for purity analysis. In this new method, ultra-high-purity and high-purity nitrogen were used as carrier gases. The impurities in high-purity nitrogen were quantitatively analyzed by comparing the differences in the area values of the GC chromatograms of the prepared CRMs. We purchased liquid nitrogen and three bottles of nitrogen gas, which were produced by three different manufacturers, using high-purity nitrogen. Furthermore, to validate the developed purity analysis method, the fraction of impurities in high-purity nitrogen was compared with the results of the typical purity analysis method. The comparison results were consistent within the expanded uncertainties (k = 2).

The Effect of the Purity of Raw Materials on the Purity of Silicon Extracted by Solvent Refining and Centrifugation (용매정제법과 원심분리법으로 추출한 Si의 순도에 미치는 장입 원재료 순도의 영향)

  • Cho, Ju-Young;Seo, Kum-Hee;Kang, Bok-Hyun;Kim, Ki-Young
    • Korean Journal of Metals and Materials
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    • v.50 no.12
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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.

Enhanced Production of Human Serum Albumin by Fed-Batch Culture of Hansenula polymorpha with High-Purity Oxygen

  • Youn, Jong-Kyu;Shang, Longan;Kim, Moon-Il;Jeong, Chang-Moon;Chang, Ho-Nam;Hahm, Moon-Sun;Rhee, Sang-Ki;Kang, Hyun-Ah
    • Journal of Microbiology and Biotechnology
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    • v.20 no.11
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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.

Purity assignment of 17α-hydroxyprogesterone by mass balance method to establish traceability in measurement

  • Lee, Hwa Shim;Park, Su Jin
    • Analytical Science and Technology
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    • v.32 no.6
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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.

Purity assignment of 17β-estradiol by mass balance method

  • Lee, Hwa-Shim;Oh, Kwang-Hoon
    • Analytical Science and Technology
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    • v.30 no.5
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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.

A Study on the Sweating Process for High Purification of p-Dioxanone (파라디옥사논의 고순도 정제를 위한 발한(sweating) 공정에 관한 연구)

  • Kim, Sung-Il;Chun, Suk-Keun;Park, Du-Goan;Park, Keun-Ho;Park, So-Jin;Kim, Chul-Ung
    • Journal of the Korean Applied Science and Technology
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    • v.24 no.2
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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.

Preparation of Colour Filter Photo Resists for Improving Colour Purity in Liquid Crystal Displays by Synthesis of Polymeric Binder and Treatment of Pigments

  • Yoon, Chun;Choi, Jae-Hong
    • Bulletin of the Korean Chemical Society
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    • v.30 no.8
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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.

Simulation of (R)- and (S)- Ketoprofen Separation in Simulated Moving Bed (SMB) ((R)-케토프로펜과 (S)- 케토프로펜 분리를 위한 유사 이동층 크로마토그래피의 전산모사)

  • Lee, Il Song;Lee, In Su;Kim, In Ho
    • KSBB Journal
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    • v.29 no.4
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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.