TITLE

Quantitative NMR spectroscopy of complex technical mixtures using a virtual reference: chemical equilibria and reaction kinetics of formaldehyde—water—1,3,5-trioxane

AUTHOR(S)
Maiwald, Michael; Grützner, Thomas; Ströfer, Eckhard; Hasse, Hans
PUB. DATE
August 2006
SOURCE
Analytical & Bioanalytical Chemistry;Aug2006, Vol. 385 Issue 5, p910
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Quantitative 1H NMR spectroscopy was used to study chemical equilibria and reaction kinetics of both the formation and decomposition of 1,3,5-trioxane in aqueous formaldehyde solutions. The reaction was homogeneously catalyzed with up to 0.10 g g−1 sulfuric acid at temperatures between 360 and 383 K so that most of the experiments had to be carried out pressurized. The studied mixtures were complex due to the formation of methylene glycol and poly(oxymethylene) glycols in aqueous formaldehyde and the presence of considerable amounts of ionized species. Most common internal standards are decomposed by the hot sulfuric acid and external standards were not applicable using the flow NMR probe or pressurizable NMR sample tubes. Therefore, for the quantification of the small trioxane signals, a novel procedure was applied, in which electronically generated NMR signals were used as highly stable Virtual References (VR). The NMR decoupler channel with wave-form generator was used as the source of the reference signal, which was irradiated into the probe using the lock coil. Details on the experimental procedure are presented. It is shown that the presented method yields reliable quantitative reaction data for the complex studied mixtures. [Figure not available: see fulltext.]
ACCESSION #
21288218

 

Related Articles

  • Biophysics: Watching proteins in motion.  // Nature Methods;Nov2012, Vol. 9 Issue 11, p1047 

    The article offers information on a research on proteins in which it was found that nuclear magnetic resonance (NMR) spectroscopy can be used for studying molecular dynamics.

  • Stereochemistry of Seven-membered Heterocycles: XLIV. Spatial Structure of 4-R-3,5-Dioxabicyclo[5.1.0]octanes. Fedorenko, V.; Baryshnikov, R.; Khairutdinov, B.; Vafina, R.; Shtyrlin, Yu.; Klochkov, V.; Klimovitskii, E. // Russian Journal of Organic Chemistry;Feb2005, Vol. 41 Issue 2, p293 

    4-R-3,5-Dioxabicyclo[5.1.0]octanes were prepared in good yields by reduction of the corresponding 8,8-dichloro derivatives in a system Li- t-BuOH. According to the data of dynamic 1H and 13CNMR spectroscopy involving experiments in the NOESY mode the formal (R = H) at -93�C in (CD3)2CO...

  • Beta-NMR spectroscopy: Modern state and prospects. Abov, Yu.; Gulko, A.; Dzheparov, F. // Physics of Atomic Nuclei;Oct2006, Vol. 69 Issue 10, p1701 

    Fundamentals of the method of beta-NMR spectroscopy are outlined, and basic types of investigations performed thus far and possible new lines of investigations are surveyed.

  • Chemical constituents with antioxidant activity from the pericarps of Juglans sigillata. Chuan-Ling Si; Yu Zhang; Zhen-Yuan Zhu; Shi-Chao Liu // Chemistry of Natural Compounds;Jul2011, Vol. 47 Issue 3, p442 

    The article presents a study which investigates the antioxidant and biological activities of chemical constituents on the fresh pericarps of Juglans sigillata (Juglandaceae). It states that fresh pericarps from J. sigillata were collected from Santai of Sichuan province in China and were...

  • McMaster U's facilities earn Health Canada approval. Lougheed, Tim // Canadian Chemical News;Jan/Feb2016, p16 

    The article reports that McMaster University in Hamilton, Ontario, has obtained Health Canada Drug Establishment License (DEL) for nuclear magnetic resonance (NMR) spectroscopy labs in the country which is also a site with equipments for analytical activities. It mentions that the analytical...

  • News Spectrum.  // Spectroscopy;Oct2008, Vol. 23 Issue 10, p12 

    The article offers news briefs related to spectroscopy in the U.S. The Cornell Univesity's researchers used proton nuclear magnetic resonance spectrometry and mass spectrometry in studying the molecular structure of brown spider venom. Research at the Massachusetts Institute of Technology...

  • One- and two-dimensional exchange J-resolved CP-MAS NMR spectrum of adamantane. Takegoshi, K.; McDowell, C. A. // Journal of Chemical Physics;2/15/1986, Vol. 84 Issue 4, p2084 

    A combined technique of 1D and 2D exchange NMR and J-resolved CP-MAS NMR of dilute spins in solids and its application to study a spin exchange process of abundant spins in solids is described, and demonstrated for powdered adamantane. A high-resolution J-resolved NMR spectrum of a 13C nucleus...

  • NMR and CD analysis of an intermediate state in the thermal unfolding process of mouse lipocalin-type prostaglandin D synthase. Miyamoto, Yuya; Noda, Yasuo; Iida, Tsukimi; Yamaguchi, Keisuke; Nishimura, Shigenori; Tanaka, Akiyoshi; Segawa, Shin-ichi; Inui, Takashi // Journal of Biochemistry;Mar2012, Vol. 151 Issue 3, p335 

    We previously reported that the thermal unfolding of mouse lipocalin-type prostaglandin D synthase (L-PGDS) is a completely reversible process under acidic conditions and follows a three-state pathway, including an intermediate state (I) between native state (N) and unfolded state. In the...

  • Determination of Components in Paracetamol, Aminophenazone, Caffeine and Chlorphenamine Maleate Tablets Using ¹H-Nuclear Magnetic Resonance Spectrosopy. TANG Gang-feng; BAO Hui-min; ZHAO Bin; ZHU Wan-sen; LEI jie // Research & Exploration in Laboratory;Jun2014, Vol. 33 Issue 6, p5 

    An instrumental analysis experiment was introduced : simultaneous identification and quantitative determination of components in Paracetamol, Aminophenazone, Caffeine and Chlorphenamine Maleate Tablets using 1HNuclear Magnetic Resonance Spectroscopy. This paper introduces the purpose, procedure...

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics