Liquid chromatography/proton nuclear magnetic resonance spectrometry average composition analysis of fuels

Journal Article · Sat Jan 01 04:00:00 EST 1983 · Anal. Chem.; (United States)

DOI:https://doi.org/10.1021/ac00252a009· OSTI ID:5058056

Haw, J F; Glass, T E; Dorn, H C

The use of a NMR spectrometer as a continuous flow liquid chromatographic detector (LC//sup 1/H NMR) generates a proton spectrum of each hydrocarbon class present in the sample. A detailed set of equations is presented which permits LC//sup 1/H NMR integration data from petroleum fuels to be interpreted as an average composition for each chromatographic fraction. Quantities calculated for each aromatic fraction include: the number average molecular weight, average degree of substitution on aromatic rings, the absolute number of moles of each structural type of carbon, an average structure (devoid of stereoisomer information), the total number of moles of carbon in each chromatographic fraction, and numerous other properties of interest in fuel characterization. The method is demonstrated for artifical fuels of known composition, for two experimental aviation fuels, and for a fuel blending stock sample which had been fully characterized at an independent laboratory by gas chromatography and GC/MS. The LC//sup 1/H NMR average composition method is shown to be very accurate for the monocyclic aromatic (substituted benzenes and tetralins) and dicyclic aromatic (substituted naphthalenes and acenaphthenes) fractions of petroleum fuels. Average molecular weights for these fractions can be routinely determined at an accuracy of +/-4 daltons. The other quantities are also determined at a high degree of accuracy. The applicability of the LC//sup 1/H NMR method to the aliphatic fraction of fuel samples is restricted by difficulties in accounting for quaternary carbons and cycloalkanes.

• Research Organization: Virginia Polytechnic Inst. and State Univ., Blacksburg
• OSTI ID: 5058056
• Journal Information: Anal. Chem.; (United States), Journal Name: Anal. Chem.; (United States) Vol. 55:1; ISSN ANCHA
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
016000* -- Coal
Lignite
& Peat-- Health & Safety
AROMATICS
BARYONS
CHROMATOGRAPHY
DATA
ELEMENTARY PARTICLES
EXPERIMENTAL DATA
FERMIONS
HADRONS
INFORMATION
LIQUID COLUMN CHROMATOGRAPHY
MAGNETIC RESONANCE
MOLECULAR STRUCTURE
MOLECULAR WEIGHT
NUCLEAR MAGNETIC RESONANCE
NUCLEONS
NUMERICAL DATA
ORGANIC COMPOUNDS
PETROLEUM PRODUCTS
PROTONS
RESONANCE
SEPARATION PROCESSES