• 제목/요약/키워드: methods:analytical

검색결과 3,013건 처리시간 0.032초

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
    • /
    • 제25권4호
    • /
    • pp.517-524
    • /
    • 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
    • /
    • 제8권6호
    • /
    • pp.615-630
    • /
    • 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.

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

  • 윤태영
    • 한국도로학회논문집
    • /
    • 제18권3호
    • /
    • pp.21-32
    • /
    • 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.

석면 분석방법에 대한 고찰 (Review on asbestos analysis)

  • 함승헌;황성호;윤충식;박동욱
    • 한국산업보건학회지
    • /
    • 제19권3호
    • /
    • pp.213-232
    • /
    • 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.

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

  • 이세정;권민섭;한웅호;문효;최선일;이옥환
    • 식품과학과 산업
    • /
    • 제55권1호
    • /
    • pp.23-32
    • /
    • 2022
  • 제외국에는 지정되었지만 국내에는 아직 미지정된 식품첨가물의 종류가 많다. 전세계적으로 가공식품이 꾸준히 개발됨에 따라 새로운 유형의 가공식품의 등장이 증가하고 있으며, 국가별로 수출입에 관한 법률 규정이 상이하여 우리나라에서는 안전성 검정 및 사용량 제한이 되어있지 않은 식품첨가물을 이용한 새로운 가공식품이 국내 수입식품 중 혼입되어 유통될 수 있다. 이에 따라 국민의 안전한 먹거리를 보장하기 위한 지속적인 모니터링을 하기 위하여 미지정 식품첨가물의 분석법 개발이 필요하다. 본 고에서는 학계에서 진행된 분석법 개발과 검증에 대한 연구를 소개하였으며, 선행연구에서 제시된 분석법을 활용하여 분석법 개발을 진행하였다. 첫 번째 소개된 12가지 식품 착색료에 대한 동시분석법은 선행연구 분석법의 재현이 용이하였지만, 두 번째 소개된 유화제의 분석법은 일반적인 연구실에는 구비되지 않은 고가의 장비를 이용한 분석법에 대해 활용이 불가하고, 선행 연구된 간행물이 오래되어 재현이 어려운 문제점이 있었다. 가공식품 시장이 커지면서 식품첨가물이 신생되기도 하고, 까다로운 분석물질이 등장함에 따라 미지정 식품첨가물의 분석법 개발 연구는 중요하다. 따라서 이에 관련된 국가기관(식약처 등)과 산업계, 연구계, 학계에서는 미지정 식품첨가물의 분석법 개발에 대한 끊임없는 연구 진행이 필요하며, 본 연구 분야의 발전 가능성은 무궁무진할 것으로 사료된다.

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
    • 한국지하수토양환경학회:학술대회논문집
    • /
    • 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
    • /
    • pp.223-226
    • /
    • 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.

  • PDF

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

  • 정다위;전태완;신선경
    • 분석과학
    • /
    • 제19권2호
    • /
    • pp.163-171
    • /
    • 2006
  • 우리나라 지정폐기물에 함유된 오염물질 분석방법을 제시하기 위해 오니, 폐유, 소각재 등 폐기물 인증표준물질을 확보하여 중금속 종류별 기기별 전처리 방법을 적용 실험하였다. 지정폐기물에 함유된 As, CN, Cd, Cr, Cu, Pb, Hg 7개 항목에 대한 함량시험방법을 제시하였다. 특히, 동일한 전처리 방법이 여러 항목에 적용될 수 있는지를 검토하고, 이들 항목 배출 가능성이 있는 34개 업소 표본사업장을 선정하여 폐기물 시료를 채취하고 제시한 분석방법으로 적용실험을 수행하였다.

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
    • 국제학술발표논문집
    • /
    • The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
    • /
    • pp.176-181
    • /
    • 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.

  • PDF

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
    • /
    • 제8권4호
    • /
    • pp.69-78
    • /
    • 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.

준해석 설계민감도를 위한 변위하중법 (Displacement-Load Method for Semi-Analytical Design Sensitivity Analysis)

  • 유정훈;김흥석;이태희
    • 대한기계학회논문집A
    • /
    • 제28권10호
    • /
    • pp.1590-1597
    • /
    • 2004
  • Three methods of design sensitivity analysis for structures such as numerical method, analytical method and semi-analytical method have been developed for the last three decades. Although analytical design sensitivity analysis can provide very exact result, it is difficult to implement into practical design problems. Therefore, numerical method such as finite difference method is widely used to simply obtain the design sensitivity in most cases. The numerical differentiation is sufficiently accurate and reliable fur most linear problems. However, it turns out that the numerical differentiation is inefficient and inaccurate in nonlinear design sensitivity analysis because its computational cost depends on the number of design variables and large numerical errors can be included. Thus the semi-analytical method is more suitable for complicated design problems. Moreover, semi-analytical method is easy to be performed in design procedure, which can be coupled with an analysis solver such as commercial finite element package. In this paper, implementation procedure fur the semi-analytical design sensitivity analysis outside of the commercial finite element package is studied and the computational technique is proposed for evaluating the partial differentiation of internal nodal force, so called pseudo-load. Numerical examples coupled with commercial finite element package are shown to verify usefulness of proposed semi-analytical sensitivity analysis procedure and computational technique for pseudo-load.