• 제목/요약/키워드: chemical identification

검색결과 931건 처리시간 0.026초

Synthesis of N$^6$-Aminoalkyl-5'-adenylic Acid Derivatives

  • Kang, Jung-Bu
    • Bulletin of the Korean Chemical Society
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    • 제1권4호
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    • pp.126-131
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    • 1980
  • Seventeen new $N^{6}$-aminoalkyl derivatives of 5'-adenylic acid and adenosine 5'-triphosphate (Compound I-XVII) were synthesized from 6-chloropurine ribonucleoside by reaction with appropriate diamines. This paper discusses the procedure of synthesis and the identification of the derivatives by ultraviolet spectra, high voltage electrophoresis, paper chromatography, elemental analyses, and other chemical methods.

다변량 통계 분석을 이용한 결측 데이터의 예측과 센서이상 확인 (Missing Value Estimation and Sensor Fault Identification using Multivariate Statistical Analysis)

  • 이창규;이인범
    • Korean Chemical Engineering Research
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    • 제45권1호
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    • pp.87-92
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    • 2007
  • 최근 공정의 이상을 감지하고 진단하기 위한 공정 모니터링 시스템의 개발이 공정 시스템 분야에서 많은 주목을 받고 있다. 공정으로부터 얻어지는 데이터는 공정의 특성에 대한 유용한 정보를 제공하고 이는 공정의 모델링과 모니터링 그리고 제어에 사용된다. 현대의 화학 및 환경 공정은 고차원적인 특성과 변수간의 강한 상관관계와 동특성 그리고 비선형적 특성을 가지고 있어 모델 기반 접근을 통해 공정을 분석하는 것을 쉽지 않다. 이러한 모델 기반 접근의 한계를 극복하기 위해 많은 시스템 엔지니어와 연구자들이 주성분 분석법(principal component analysis, PCA) 또는 부분 최소 자승법(partial least squares, PLS)과 같은 다변량 분석을 접목한 통계 기반 접근법에 초점을 맞추고 있다. 또한 동특성, 비선형성 등과 같은 특성을 가진 공정에 적용하기 위해 많은 다변량 분석법들이 보완되었다. 여기에서는 동적 주성분 분석법(dynamic PCA)과 케노니컬 변수 분석법(canonical variate analysis)을 이용한 결측 데이터의 예측법과 공정 변수의 복원을 통한 센서 오작동의 판별법에 대해 언급해 보고자 한다.

Identification of Nandrolone and its Metabolite 5α-Estran-3β, 17α-Diol in Horse Urine after Chemical Derivatization by Liquid Chromatography Tandem Mass Spectrometry

  • Dubey, Saurabh;Beotra, Alka
    • Mass Spectrometry Letters
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    • 제8권4호
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    • pp.90-97
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    • 2017
  • Androgenic anabolic steroids (AASs) are synthetic derivatives of testosterone with a common structure containing cyclopentanoperhydrophenanthrene nucleus. Their use enhances the muscle building capacity and is beneficial during performance. The AASs are one of the most abused group of substances in horse doping. Liquid chromatography tandem mass spectrometry ($LC/MS^n$) has been successfully applied to the detection of anabolic steroids in biological samples. However, the saturated hydroxysteroids viz: nandrolone, $5{\alpha}-estrane-3{\beta}$, $17{\alpha}-diol$ exhibit lower detection responses in electrospray ionisation (ESI) because of their poor ionisation efficiency. To overcome this limitation pre-column chemical derivatization has been introduced to enhance their detection responses in $LC-ESI-MS^n$ analysis. The aim of present study was to develop a sensitive method for identification and confirmation of nandrolone and its metabolite in horse urine incorporating pre-column derivatization using picolinic acid. The method consists of extraction of targeted steroid conjugates by solid phase extraction (SPE). The eluted steroid conjugates were hydrolysed by methanolysis and free steroids were recovered with liquid-liquid extraction. The resulting steroids were derivatized to form picolinoyl esters and identification was done using LC-ESI-MS/MS in positive ionization mode. The picolinated steroid adduct enhanced the detection levels in comparison to underivatized steroids.

Rapid Detection of Bacteria from Blood Culture by an Electronic Nose

  • Lykos, Peter;Patel, Pravin H.;Morong, Christopher;Joseph, Asha
    • Journal of Microbiology
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    • 제39권3호
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    • pp.213-218
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    • 2001
  • The treatment of Patients with bacteraemia and septicemia requires accurate and rapid identification of the pathogen so that the physician can be guided regarding the selection of the proper antimicrobial therapy. The usual procedure is to withdraw an aliquot of the positive blood culture sample for gram staining and subculturing on the media for the growth and subsequent identification, and susceptibility determinations. It was noticed that during the process some microbiologists would sniff the effluent gases that are products of metabolism and in some cases guess the identity of the bacterium. That Prompted us to engage in systematic investigation of two gram positive and two gram negative bacteria using an electronic nose that had been proven successful in distinguishing the aroma of coffee beans from different sources. The investigation was successful in illustrating the efficacy of such a device in this clinical setting to distinguish Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecalis. A representative set of patterns obtained with this apparatus is displayed as well. A representative set of patterns obtained with this apparatus is displayed as well. No effort was made to determine an optimal set of sensors for some specific set of bacterial metabolism gaseous products.

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금려환(錦儷丸)의 현미감정 연구 (Microscopic Identification of the Chinese Patent Medicine 'Geum Ryeo Hwan')

  • 김정묘;박종희
    • 생약학회지
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    • 제37권2호통권145호
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    • pp.116-119
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    • 2006
  • Geum Ryeo Hwan(錦儷丸) is Chinese patent medicine which has been used for women's diseases and climacteric syndrome in Korea. It consists of 12 kinds of powdered crude drugs. In powdered crude drugs, it is hard to identify each component by chemical analysis or morphological examination. However, the method of identification of powdered crude drugs has not been clearly established. Therefore, it is of interest to establish the microscopic method for identification of powdered crude drugs of Chinese patent medicines. The effectiveness of microscopic method is exemplified by the identification of tissue and contents of crude drugs by comparison with standard drugs. Moreover, this method has advantage as a microscale analysis, since it requires only a small amount of specimens. In this study, it is demonstrated that the microscopic method is very effective for the identification of 12 crude drug ingredients in Geum Ryeo Hwan.

아명단(兒明丹)의 현미감정연구 (Microscopic Identification of the Chinese Patent Medicine 'Ah Myeong Dan')

  • 김정묘;박종희
    • 생약학회지
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    • 제36권3호통권142호
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    • pp.205-208
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    • 2005
  • Ah Myeong Dan (兒明丹) is Chinese patent medicine which is used for congenital fever and congenital boils in Korea. It consists of 11 kinds of powdered crude drugs. In powdered crude drugs, it is hard to identify each component by chemical analysis or morphological examination. However, the method of identification of powdered crude drugs has not been clearly established. Therefore, it is of interest to establish the microscopic method for identification of powdered crude drugs of Chinese patent medicines. The effectiveness of microscopic method is exemplified by the identification of tissue and contents of crude drugs by comparison with standard drugs. In this study, it is demonstrated that the microscopic method is very effective for the identification of 11 crude drug ingredients in Ah Myeong Dan.

Identification Performance of Low-Molecular Compounds by Searching Tandem Mass Spectral Libraries with Simple Peak Matching

  • Milman, Boris L.;Zhurkovich, Inna K.
    • Mass Spectrometry Letters
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    • 제9권3호
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    • pp.73-76
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    • 2018
  • The number of matched peaks (NMP) is estimated as the spectral similarity measure in tandem mass spectral library searches of small molecules. In the high resolution mode, NMP provides the same reliable identification as in the case of a common dot-product function. Corresponding true positive rates are ($94{\pm}3$) % and ($96{\pm}3$) %, respectively.

Modeling of Grade Change Operations in Paper Mills

  • Ko, Jun-Seok;Yeo, Yeong-Koo;Ha, Seong-Mun;Lim, Jung-Woo;Ko, Du-Seok;Hong Kang
    • 펄프종이기술
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    • 제35권5호
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    • pp.46-52
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    • 2003
  • In this work we developed the closed-loop model of a paper machine during grade change with the intention to provide a reliable dynamic model to be used in the model-based grade change control scheme. During the grade change, chemical and physical characteristics of paper process change with time. It is very difficult to represent these characteristics on-line by using physical process models. In this work, the wet circulation part and the drying section were considered as a single process and closed-loop identification technique was used to develop the grade change model. Comparison of the results of numerical simulations with mill operation data demonstrates the effectiveness of the model identified.

셀룰로오스와 리그닌의 열분해 생성물중의 여러고리 방향족화합물의 분리와 동정 (Separation and Identification of Polycyclic Aromatic Compounds in Pyrolysis Products of Cellulose and Lignin)

  • 박래정
    • 대한화학회지
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    • 제28권4호
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    • pp.244-250
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    • 1984
  • ${\cdot}$염기용매분배법과 규소산 칼럼 크로마토그라피법 및 용융 실리카모세관 칼럼크로마토그라피, 질량분석법을 사용하며 셀룰로오스와 리그닌의 열분해생성물중의 여러고리 방향족 화합물의 분리와 동정을 수행하였다. 16가지의 여러고리 방향족 화합물이 머무른 계수와 질량스펙트럼데이타에 의해서 확인되었다. 두가지 물질 모두에서 같은 종류의 여러고리 방향족 화합물이 생성되었으며, 그 함량에 있어서는 리그닌에서 훨씬 많은량이 생성되었다. 극히 발암성인 질소 및 유황을 함유하는 헤테로 고리 방향족 화합물은 거의 생성되지 않았다.

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