• 제목/요약/키워드: Mass Spectrometric

검색결과 259건 처리시간 0.024초

질량분석 시스템을 이용한 극지 토양 유래 신규 미생물의 지질 A 화학적 구조 분석 (Determination of Lipid A Profile of Gram-Negative Bacteria from Arctic Soils Using Mass Spectrometric Approaches)

  • 황철환;박한규;김윤곤
    • KSBB Journal
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    • 제31권4호
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    • pp.263-269
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    • 2016
  • For decades, the microorganisms in arctic soils have been newly discovered according to the climate change and global warming. In this study, the chemical structure of a lipid A molecule from Pseudomonas sp. strain PAMC 28615 which was newly discovered from arctic soils was characterized by mass spectrometric approaches such as matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) and MALDI multi-stage tandem mass spectrometry (MS). First, lipopolysaccharide (LPS) from Pseudomonas sp. strain PAMC 28615 was extracted and subsequently hydrolyzed to obtain the lipid A. The parent ion peak at m/z 1632 was determined by MALDI-TOF MS, which also can validate our lipid A purification method. For detailed structural determination, we performed the multiple-stage tandem mass analysis ($MS^4$) of the parent ion, and subsequently the abundant fragment ions in each MS stage are tested. The fragment ions in each MS stage were produced from the loss of phosphate groups and fatty acyl groups, which could be used to confirm the composition or the position of the lipid A components. Consequently, the mass spectrometry-based lipid A profiling method could provide the detail chemical structure of lipid A from the Pseudomonas sp. strain PAMC 28615 as an arctic bacterium from the frozen arctic soil.

Kinetic Energy Release in the Fragmentation of tert-Butylbenzene Molecular Ions. A Mass-analyzed Ion Kinetic Energy Spectrometric (MIKES) Study

  • Choe, Joong-Chul;Kim, Byung-Joo;Kim, Myung-Soo
    • Bulletin of the Korean Chemical Society
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    • 제10권2호
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    • pp.167-171
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    • 1989
  • Kinetic energy release in the fragmentation of tert-butylbenzene molecular ion was investigated using mass-analyzed ion kinetic energy spectrometry. Method to estimate kinetic energy release distribution (KERD) from experimental peak shape has been explained. Experimental KERD was in good agreement with the calculated result using phase space theory. Effect of dynamical constraint was found to be important.

Development of an Isotope-Dilution Flow-Injection Electrospray/ Mass Spectrometric Method for the Accurate Determination of Glucosamine in Pharmaceutical Formulation

  • Kim, Gui-Nam;Kim, Byung-Joo;Ahn, Seong-Hee;Hwang, Eui-Jin;Kim, Yong-Seong
    • Bulletin of the Korean Chemical Society
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    • 제30권2호
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    • pp.363-367
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    • 2009
  • An isotope-dilution flow-injection electrospray/mass spectrometric method was developed for the accurate determination of glucosamine contents in pharmaceutical formulations. Samples were extracted by methanol. After spiking glucosamine-1-$^{13}C_1$ as an internal standard, the extracts were then analyzed by flow-injection ESI/MS in a selected ion monitoring (SIM) mode to detect [M+H]$^+$ ions of the analyte and its isotope analogue at m/z 180 and m/z 181, respectively. Confirmatory measurements were made by selectively monitoring the collisionally induced dissociation channels of m/z 180 $\rightarrow$ m/z 72 and m/z 181 $\rightarrow$73, respectively, to test the possibility of bias in the SIM method due to matrix interferences, but any significant bias in the SIM mode was not observed. Repeatability and reproducibility studies showed that the flow-injection ESI/MS method is a reliable and reproducible method which can provide a typical method precision of 1.0 %. Other results for the method validation are reported.

Development of an Isotope-Dilution Liquid Chromatography/Mass Spectrometric Method for the Accurate Determination of Acetaminophen in Tablets

  • Shin, Hyun-Ju;Kim, Byung-Joo;Lee, Joon-Hee;Hwang, Eui-Jin
    • Bulletin of the Korean Chemical Society
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    • 제31권12호
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    • pp.3663-3667
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    • 2010
  • Acetaminophen (N-acetyl-p-aminophenol) is one of the most popular analgesic and antipyretic drugs. An isotope dilution mass spectrometric method based on LC/MS was developed as a candidate reference method for the accurate determination of acetaminophen in pharmaceutical product. After spiking an isotope labeled acetaminophen (acetyl-$^{13}C_2$, $^{15}N$-acetaminophen) as an internal standard, tablet extracts were analyzed by LC/MS in a selected reaction monitoring (SRM) mode to detect ions at m/z $152{\rightarrow}110$ and m/z $155{\rightarrow}111$ for acetaminophen and acetyl-$^{13}C_2$, $^{15}N$-acetaminophen, respectively. The repeatability and reproducibility of the developed ID/LC-MS method were tested for the validation and assessment of metrological quality of the method.