• Title/Summary/Keyword: methods: analytical

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Development of the Standard Analytical Methods for Ginkgo biloba Leaf Extract (은행엽엑스 제제의 기준 및 시험법과 규격 설정)

  • Kim, Seung-Hyun;Kim, Dae-Hyun;Park, Jin-Ho;Oh, Mi-Hyune;Cho, Chang-Hee;Baek, Ju-Hyun;Cho, Jung-Hee;Kim, Tae-Bum;Lee, Ki-Yong;Kim, Young-Choong;Sung, Sang-Hyun
    • Korean Journal of Pharmacognosy
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    • v.39 no.3
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    • pp.218-222
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    • 2008
  • This study was carried out to establish standard analytical methods for Ginkgo biloba leaf extract. Ginkgo flavonoids, terpene lactones, ginkgolic acids were employed as reference compounds for analytical method. Analytical method of US Pharmacopoeia was adopted for flavonoids and terpene lactones, and a new method was developed for ginkgolic acids. Analytical methods established in this study could be applied to a reasonable and unified quality control of G. biloba leaf extract.

Spectrophotometric and Kinetic Determination of Some Sulphur Containing Drugs in Bulk and Drug Formulations

  • Walash, M.I.;El-Brashy, A.M.;Metwally, M.S.;Abdelal, A.A.
    • Bulletin of the Korean Chemical Society
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    • v.25 no.4
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    • pp.517-524
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    • 2004
  • Two simple and sensitive spectrophotometric methods were developed for the determination of carbocisteine, penicillamine, ethionamide and thioctic acid in bulk and in their pharmaceutical preparations using alkaline potassium permanganate as an oxidizing agent. The first one involves determination of ethionamide and thioctic acid by spectrophotometric investigation of the oxidation reaction of the two drugs. The second method involves determination of carbocisteine and penicillamine by kinetic studies of the oxidation reaction of these two drugs at room temperature for a fixed time of 20 minutes. The absorbance of the colored manganate ions was measured at 610 nm in both methods. 1-10 ${\mu}$g/mL of ethionamide and thioctic acid could be etermined by the spectrophotometric method with detection limits of 0.11 and 0.089 ${\mu}$g/mL for the two drugs respectively. 2-10 ${\mu}$g/mL of carbocisteine and penicillamine could be determined by the kinetic method with detection limits of 0.14 and 0.21 ${\mu}$g/mL respectively. The two methods were successfully applied for the determination of these drugs in their dosage forms.

A unified solution for vibration analysis of plates with general structural stress distributions

  • Yang, Nian;Chen, Lu-Yun;Yi, Hong;Liu, Yong
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.8 no.6
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    • pp.615-630
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    • 2016
  • Complex stress distributions often exist in ocean engineering structures. This stress influences structural vibrations. Finite Element Methods exhibit some shortcomings for solving non-uniform stress problems, such as an unclear physical interpretation, complicated operation, and large number of computations. Analytical methods research considers mainly uniform stress problems, and often, their methods cannot be applied in practical marine structures with non-uniform stress. In this paper, an analytical method is proposed to solve the vibration of plates with general stress distributions. Non-uniform stress is expressed as a special series, and the stress influence is inserted into a vibration equation that is solved through decoupling to obtain an analytical solution. This method has been verified using numerical examples and can be used in arbitrary stress distribution cases. This method requires fewer computations and it provides a clearer physical interpretation, so it has advantages in some qualitative research.

Review on Analytical Solutions for Slump Flow of Cement Paste (시멘트 페이스트의 슬럼프 유동 모사를 위한 분석적 해의 검토)

  • Yun, Taeyoung
    • International Journal of Highway Engineering
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    • v.18 no.3
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    • pp.21-32
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    • 2016
  • PURPOSES : In this paper, the analytical solutions suggested to simulate the behavior of rheological fluids were rigorously re-derived and investigated for fixed conditions to evaluate the applicability for the solutions on a mini-cone slump test of cement paste. The selected solutions with proper boundary conditions can be used as reference solutions to evaluate the performance of numerical simulation approaches, such as the discrete element method. METHODS : The slump, height, and spread radius for the given boundary and yield stress conditions that are determined by five different analytical solutions are compared. RESULTS : The analytical solution based on fluid mechanics for pure shear flow shows similar results to that for intermediate flow at low yield stresses. The fluid mechanics-based analytical solution resulted in a very similar trend to the geometry-based analytical solution. However, it showed a higher slump at high yield stress and lower slump at low yield stress ranges than the geometry-based analytical model. The analytical solution based on the mini-cone geometry was not significantly affected by the yield criteria, such as von Mises and Tresca. CONCLUSIONS : Even though differences among the analytical solutions in terms of slump and spread radius existed, the difference can be considered insignificant when the solutions were used as reference to evaluate the appropriateness of numerical approaches, such as the discrete element method.

Review on asbestos analysis (석면 분석방법에 대한 고찰)

  • Ham, Seung hon;Hwang, Sung Ho;Yoon, Chungsik;Park, Donguk
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.19 no.3
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    • pp.213-232
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    • 2009
  • This document was prepared to review and summarize the analytical methods for airborne and bulk asbestos. Basic principles, shortcomings and advantages for asbestos analytical instruments using phase contrast microscopy(PCM), polarized light microscopy(PLM), X-ray diffractometer (XRD), transmission electron microscopy(TEM), scanning electron microscopy(SEM) were reviewed. Both PCM and PLM are principal instrument for airborne and bulk asbestos analysis, respectively. If needed, analytical electron microscopy is employed to confirm asbestos identification. PCM is used originally for workplace airborne asbestos fiber and its application has been expanded to measure airborne fiber. Shortcoming of PCM is that it cannot differentiate true asbestos from non asbestos fiber form and its low resolution limit ($0.2{\sim}0.25{\mu}m$). The measurement of airborne asbestos fiber can be performed by EPA's Asbestos Hazard Emergency Response Act (AHERA) method, World Health Organization (WHO) method, International Standard Organization (ISO) 10312 method, Japan's Environmental Asbestos Monitoring method, and Standard method of Indoor Air Quality of Korea. The measurement of airborne asbestos fiber in workplace can be performed by National Institute for Occupational Safety and Health (NIOSH) 7400 method, NIOSH 7402 method, Occupational Safety and Health Administration (OSHA) ID-160 method, UK's Health and Safety Executive(HSE) Methods for the determination of hazardous substances (MDHS) 39/4 method and Korea Occupational Safety and Health Agency (KOSHA) CODE-A-1-2004 method of Korea. To analyze the bulk asbestos, stereo microscope (SM) and PLM is required by EPA -600/R-93/116 method. Most bulk asbestos can be identified by SM and PLM but one limitation of PLM is that it can not see very thin fiber (i.e., < $0.25{\mu}m$). Bulk asbestos analytical methods, including EPA-600/M4-82-020, EPA-600/R-93/116, OSHA ID-191, Laboratory approval program of New York were reviewed. Also, analytical methods for asbestos in soil, dust, water were briefly discussed. Analytical electron microscope, a transmission electron microscope equipped with selected area electron diffraction (SAED) and energy dispersive X-ray analyser(EDXA), has been known to be better to identify asbestiform than scanning electron microscope(SEM). Though there is no standard SEM procedures, SEM is known to be more suitable to analyze long, thin fiber and more cost-effective. Field emission scanning electron microscope (FE-SEM) imaging protocol was developed to identify asbestos fiber. Although many asbestos analytical methods are available, there is no method that can be applied to all type of samples. In order to detect asbestos with confidence, all advantages and disadvantages of each instrument and method for given sample should be considered.

A study on the development of analytical methods for undesignated food additives in Korean foods (국내 미지정 식품첨가물의 식품 중 분석법 개발에 관한 고찰)

  • Lee, Se-Jeong;Kwon, Min-Seop;Han, Xionggao;Men, Xiao;Choi, Sun-Il;Lee, Ok-Hwan
    • Food Science and Industry
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    • v.55 no.1
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    • pp.23-32
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    • 2022
  • Processed foods using food additives designated as the other countries but not yet in Korea can be mixed and distributed among imported foods in Korea. Accordingly, it is necessary to develop an analysis method of undesignated food additives in order to continuously monitor. This paper introduced a study on the development and validation of analytical methods conducted in academia. The development of analytical methods was conducted using the analytical methods presented in previous studies. We first exhibited that simultaneous analysis of 12 food dyes was easy to reproduce, but the second introduced analytical method of emulsifiers cannot be utilized analysis using expensive equipment not provided in general laboratories, and it is difficult to reproduce due to the old publications. Therefore related national institutions, research and industry-academia circles need to constantly conduct research on the development of analytical methods for undesignated food additives.

Comparison of USEPA Digestion Methods for Trace Metal Analysis Using SRM

  • Shin, Mi-Young;Yoon, Hyeon;Kim, Youn-Tae;Yoon, Cheol-Ho;Woo, Nam-Chil
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2004.09a
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    • pp.223-226
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    • 2004
  • The importance of a proper sample preparation and analysis technique has getting attention due to the complicity of toxic elements of interest from environmental samples depend on analytical purposes. It is critical to use proper analytical method to evaluate trace elements concentration in many environmental samples especially for making remediation decisions. Therefore, it is critical to apply a proper sampling and analytical method such as EPA publication SW-846 (Test Methods for Evaluating Solid Waste, Physical/chemical Methods). The objective of this study was to compare the USEPA Methods 3050B, modified 3050B, 305 la, and KBSI method (modified EPA 3052 Method) in term of recovery rate of metals. The NIST SRM (Montana soil) was used to compare the extraction and digestion efficiency. After sample has been collected the analysis were achieved by ICP-MS (Elan 6100, Perkin Elmer) as well as ICP-AES (Ultima 2C, JY) for trace elements and major elements.

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Evaluation of analytical methods for heavy metals and cyanide by certified reference materials (인증표준물질을 이용한 중금속류와 시안화물 전처리방법 비교 연구)

  • Chung, David;Jeon, Tae Wan;Shin, Sun Kyoung
    • Analytical Science and Technology
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    • v.19 no.2
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    • pp.163-171
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    • 2006
  • This study was performed to develop an analytical method in specified wastes for preventing the environmental pollution from hazardous wastes. Few analytical methods were developed using the waste standard reference materials of sludge, waste oil, bottom ash, etc. which contain As, CN, Cd, Cr, Cu, Pb, and Hg compounds. The pre-treatment method was considered by whether or not the synchronous analysis is possible. Waste samples obtained from the 34 representative facilities, which are emitting the hazardous substances, were analyzed.

DATA MININING APPROACH TO PARAMETRIC COST ESTIMATE IN EARLY DESIGN STAGE AND ANALYTICAL CHARACTERIZATION ON OLAP (ON-LINE ANALYTICAL PROCESSING)

  • JaeHo Cho;HyunKyun Jung;JaeYoul Chun
    • International conference on construction engineering and project management
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    • 2011.02a
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    • pp.176-181
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    • 2011
  • A role of cost modeler is that of facilitating design process by the systematic application of cost factors so as to maintain sensible and economic relationships between cost, quantity, utility and appearance. These relationships help to achieve the client's requirements within an agreed budget. The purpose of this study is to develop a parametric cost estimating model for the early design stage by using the multi-dimensional system of OLAP (On-line Analytical Processing) based on the case of quantity data related to architectural design features. The parametric cost estimating models have been adopted to support decision making in the early design stage. These models typically use a similar instance or a pattern of historical case. In order to effectively use this type of data model, it is required to set data classification and prediction methods. One of the methods is to find the similar class in line with attribute selection measure in the multi-dimensional data model. Therefore, this research is to analyze the relevance attribute influenced by architectural design features with the subject of case-based quantity data used for the parametric cost estimating model. The relevance attributes can be analyzed by Analytical Characterization. It helps determine what attributes to be included in the OLAP multi-dimension.

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MS-Based Technologies for the Study of Site-Specific Glycosylation

  • Kim, Unyong;Oh, Myung Jin;Lee, Jua;Hwang, Hee Yeon;An, Hyun Joo
    • Mass Spectrometry Letters
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    • v.8 no.4
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    • pp.69-78
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    • 2017
  • Glycosylation, which is one of the most common post-translation modification (PTMs) of proteins, plays a variety of crucial roles in many cellular events and biotherapeutics. Recent advances have led to the development of various analytical methods employing a mass spectrometry for glycomic and glycoproteomic study. However, site-specific glycosylation analysis is still a relatively new area with high potential for technologies and method development. This review will cover current MS-based workflows and technologies for site-specific mapping of glycosylation ranging from glycopeptide preparation to MS analysis. Bioinformatic tools for comprehensive analysis of glycoprotein with high-throughput manner will be also included.