Record Display for the EPA National Library Catalog

RECORD NUMBER: 50 OF 108

OLS Field Name OLS Field Data
Main Title High Sensitivity Fourier Transform NMR.
Author Levy, George C.
CORP Author Florida State Univ., Tallahassee. Dept. of Chemistry.;Health Effects Research Lab., Research Triangle Park, N.C.
Publisher U.S. EPA,
Year Published 1977
Report Number EPA 600/1-77-045; EPA-803095
Stock Number PB-274 011
Additional Subjects Nuclear magnetic resonance ; Environmental surveys ; Toxicology ; Feasibility ; Design criteria ; Fourier analysis ; Performance evaluation ; Revisions ; Samples ; Molecular relaxation ; Chemical bonds ; Chlorine organic compounds ; Complex compounds ; Carbon 13 ; Isotopic labeling ; Chemical analysis ; Toxic substances ; Polychlorinated biphenyls ; Molecular biology
Internet Access
Description Access URL
http://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=91004MR4.PDF
Holdings
Library Call Number Additional Info Location Last
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Status
NTIS  PB-274 011 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 01/01/1988
Collation 84 p. pap.
Abstract
This project explored the feasibility of developing new techniques for evaluation of the effects of environmental toxic materials on complex biopolymer systems using high sensitivity Fourier transform nuclear magnetic resonance (nmr) spectroscopy. Commercial instrumentation available in 1974-75 did not possess adequate sensitivity, and thus one goal of this project was to increase spectral sensitivity, especially for the 13C and other nuclides having low magnetogyric ratios. Initially, modifications to an existing Bruker HX-270 spectrometer provided moderate improvement in sensitivity for 13C and substantial sensitivity increase for 15N observation. During the second (last) year of this grant, a new instrument design was initiated. Several studies were begun to elucidate the nature of chlorophenol interactions in liquids, and when incorporated into lecithin bilayer membrane models. Variable frequency 13C spin lattice relaxation time measurements were used to probe cooperativity of molecular chain dynamics in some simple molecules and in two complex synthetic polymers. A new theoretical modification involving a non-exponential autocorrelation function and also allowing for multiple independent internal rotations, allowed effective analysis of a large experimental set.