• 분석과학
• /
• 제12권4호
• /
• pp.346-353
• /
• 1999

For the non-destructive multi-elemental analysis of environmental and biological materials, instrumental neutron activation analysis (INAA) was applied for the determination of toxic and trace elements in a set of three Algae samples provided by the International Atomic Energy Agency (IAEA). The analytical quality control was evaluated by comparing the analytical results of two standard reference materials of the National Institute of Standards and Technology (NIST); Oyster Tissue (SRM 1566a) and Citrus Leaves (SRM 1572). According to given analytical procedure, the concentration of 15-25 elements including spiked elements such as As, Cd, Cr and Hg in Algae samples were determined. To identify and validate these results, a data intercomparison program using more than 35 analytical methods in 150 laboratories was carried out and the estimated statistical data are summarized. Result of INAA is favorable, therefore, it is illustrated that can be applied for routine analysis of essential and toxic elements in algae samples as well as analytical quality assurance.

• Mass Spectrometry Letters
• /
• 제9권1호
• /
• pp.30-36
• /
• 2018

A quantitation method for free amino acids in human serum was developed using a stepwise-dilution method and a bimodal cation exchange (CEX)/hydrophilic interaction liquid chromatography (HILIC)-tandem mass spectrometry system equipped with an electrospray ionization source (ESI/MS/MS). This method, which was validated using quality control samples, was optimized for enhanced selectivity and sensitivity. Dithiothreitol (DTT) was used as a reducing agent to prevent the oxidation of a serum sample ($50{\mu}L$), which was then subjected to stepwise dilution using 3, 30, and 90 volumes of acetonitrile containing 0.1% formic acid. Chromatographic separation was performed on an Imtakt Intrada Amino Acid column ($50mm{\times}3mm$, $3{\mu}m$) in mixed mode packed with CEX and HILIC ligands embedded in the stationary phase. Underivatized free amino acids were eluted and separated within 10 min. As a result of the validation, the precision and accuracy for the inter- and intraday assays were determined as 2.11-11.51% and 92.82-109.40%, respectively. The lowest limit of quantification (LLOQ) was $0.5-4.0{\mu}g/mL$ and the matrix effect was 80.22-115.93%. The proposed method was successfully applied to the quantitative analysis of free amino acids in human serum.

• 분석과학
• /
• 제24권6호
• /
• pp.414-420
• /
• 2011

본 연구에서는 알파선, 베타선 및 감마선 방출 핵종에 대한 검출기를 선정하여, 방사성 시료의 핵종분석을 위한 방사선 측정 시스템을 연구하고 구성하였다. 그리고 알파, 베타 및 감마 측정 시스템에 대한 검출효율을 교정하였다. 방사선 검출기에 대한 안정도를 확보하기 위해 품질관리 프로그램이 확립되었다. 또한 분석결과에 대한 신뢰도를 확보하기 위해 시료유형에 따른 최소검출방사능을 구하였다.

• 분석과학
• /
• 제13권2호
• /
• pp.179-188
• /
• 2000

대기환경시료인 도시분진시료와 인공적으로 준비한 휠터상 도시분진시료중의 미량원소를 중성자방사화분석법을 사용하여 비파괴 분석하였다. 분석정도관리를 위하여 미국 표준기술원의 인증표준시료 (Urban Dust, NIST SRM 1648)를 이용하였다. 37종의 검출된 원소의 상대오차와 상대 표준편차를 계산하였으며 각각 10%와 15%이내이었다. 도시분진시료로부터 29종의 원소, 휠터상 도시분진시료로부터 21종의 원소를 정량하였다. 측정결과의 신뢰도 및 숙련도 평가를 위하여, 중성자방사화분석법, 하전입자유도 X-선방출분광법, X-선 형광분석법과 원자흡수분광법을 이용한 세계 39개 실험실이 참여한 실험실간 비교시험에 참여하였으며 수집된 결과를 통계처리하였다. 평균값과 표준편차로 계산한 z-score는 몇개의 원소를 제외하고 모두 -1

• 한국산업보건학회지
• /
• 제4권1호
• /
• pp.96-102
• /
• 1994

Factors affecting non-proficient analytical ability were compared and evaluated by rating of laboratories and round. Analyst Indices between proficient and non-proficient participants were different. Coefficients of determination($R^2$) for standard of toluene, xylene and trichloroethylene of the 4th round between some proficient and non-proficient participants were significantly different(p<0.05). But, there was no difference in the 5th round. Average desorption efficiency of non-proficient participants was 88%-98%, which was lower than 96%-100% of some randomly selected proficient participants. Also non-proficient participants have a large variance of desorption efficiency, 11.79-19.69%. In the 5th round, desorption efficiency of metyl iso-butyl ketone(MIBK) reported by all participants was lower than 90% tested by NIOSH and especially low compared to other analytes. Participants evaluated to be non-proficient in the metal part have 85%-100.84% of average recovery, which was larger variance than 98% of some proficient participants. Although it is difficult to find quantitatively factors causing non-proficiency in analytical ability, pretreatement techniques and experience of analyst seems to be more important factors to produce accurate analytical result.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1995년도 봄 학술발표회 논문집
• /
• pp.231-236
• /
• 1995

The object of this thesis is an analytical study on flexural deformation of high strength concrete structures using reliability theory. Using the established experimental data that have been presented in various documents the stress-strain relationship curves of high strength(500kgf/$\textrm{cm}^2$)models are proposed. Based on both methods of logarithm regression analysis and multiple regression analysis adopted in order to establish the relationships between design parameters, response random variables and flexural deformation analyzed using Monte Carlo simulation and Simpson composite formula. Additional random variables are introduced to incorporate both the confidence in the analytical accuracy of engineering mechanics associated with structural response quantities and the uncertainty in the construction quality control. The result is expected to accomodate other important design parameter of high strength concrete design in treating reliability theory that practicing engineers, structural engineering often face.

• Journal of Pharmaceutical Investigation
• /
• 제41권1호
• /
• pp.25-30
• /
• 2011

Recently, Korean Food and Drug Administration (KFDA) has focused on developing quality control guidelines for all commercial products in Korea to enforce regulations, improve the quality control, and protect consumers by developing prevalently used and efficient analytical tools to determine and quantify target compounds. Because the Korean Pharmacopeia (KP) presents microbiological assays for biotin, which is laborious and time-consuming, this study is focused on applying HPLC-UV to detect and quantify biotin in complex drugs and dietary supplements like multi-vitamin. Biotin in complex drugs was extracted from methanol and analyzed using mobile phase with 10 mM potassium phosphate (monobasic, pH=3.0) in distilled water and acetonitrile. Gradient condition was used to successfully detect and quantify biotin within 20 minutes. Validation result for linearity was significant that average $r^2$ was 0.999 (n=3) and its relative standard deviation (RSD) was 0.0578% which was less than 2%. Using this method, quantification of biotin in complex drugs was completed successfully and recovery tests were finished that recovery percentage greater than 95% with relative standard deviation less than 2%.

• International Journal of Quality Innovation
• /
• 제7권2호
• /
• pp.141-156
• /
• 2006

This study describes a novel algorithm for optimizing the quality yield of silicon wafer slicing. 12 inch wafer slicing is the most difficult in terms of semiconductor manufacturing yield. As silicon wafer slicing directly impacts production costs, semiconductor manufacturers are especially concerned with increasing and maintaining the yield, as well as identifying why yields decline. The criteria for establishing the proposed algorithm are derived from a literature review and interviews with a group of experts in semiconductor manufacturing. The modified Delphi method is then adopted to analyze those results. The proposed algorithm also incorporates the analytic hierarchy process (AHP) to determine the weights of evaluation. Additionally, the proposed algorithm can select the evaluation outcomes to identify the worst machine of precision. Finally, results of the exponential weighted moving average (EWMA) control chart demonstrate the feasibility of the proposed AHP-based algorithm in effectively selecting the evaluation outcomes and evaluating the precision of the worst performing machines. So, through collect data (the quality and quantity) to judge the result by AHP, it is the key to help the engineer can find out the manufacturing process yield quickly effectively.

• 대한약학회:학술대회논문집
• /
• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
• /
• pp.398.3-399
• /
• 2002

Quality control by analytical ability with a certain level of precision and accuracy is important. This is true especially in pharmaceutical industries. for a failure in quality control can result in a failure in drug medication. in turn. sometimes a heavy damage to patient's health condition andlor the worst damage to company's reputation. On this backgroun, Kyungki KFDA prepared test pharmaceutical products, which were distributed to 114 pharmaceutical companies in kyungin Province in year 2000. (omitted)

• 분석과학
• /
• 제33권5호
• /
• pp.224-231
• /
• 2020

With the improvement in the standard of living and extension of life expectancy, the incidence of prostate diseases has increased yearly, thus becoming a serious disease affecting the health of men. The extract mixture of Cornus officinalis and Stauntonia hexaphylla leaves is a developed functional food formula to improve prostate health. This study developed a simultaneous analytical method of bioactive compounds for quantifying the mixture of Cornus officinalis and S. hexaphylla leaves using high-pressure liquid chromatography-ultraviolet (HPLC-UV). HPLC analytical condition was performed on a Hector C₁₈ column with a mobile phase of 0.1 % formic acid in water (A) and 0.1 % formic acid in acetonitrile (B) under the following gradient conditions: 0-50 min, 12 %-40 % (B) at a flow rate of 1.0 mL/min. Meanwhile, this method was validated properly and successfully used to quantify the bioactive components of morroniside and hederacoside D in 20 sample batches and assess the quality of different ages and seasons of S. hexaphylla leaves. The result showed that the content of morroniside in the extract mixture of Cornus officinalis and S. hexaphylla leaves ranged from 1.38-1.62 mg/g, and the hederacoside D ranged from 28.42-32.02 mg/g, suggesting that this novel analytical method will be suitable for the quality control of the extract mixture to improve benign prostatic hyperplasia.