Abstract

AVELLA, Eliseo  and  FIERRO, Ricardo. UNIFIED INTEGRATION INTERVALS FOR THE STRUCTURAL CHARACTERIZATION OF OIL, COAL OR FRACTIONS THERE OF BY 1H NMR AND ¹³C NMR. Rev.Colomb.Quim. [online]. 2010, vol.39, n.1, pp.87-109. ISSN 0120-2804.

Based on an analysis of publications reported between 1972 and 2006, it became clear that there are inaccuracies in the limits of the ranges of integration that the authors assigned to signals in nuclear magnetic resonance (NMR) to the structural characterization of petroleum, coals and their derived fractions, from their hydrogen (¹H NMR) and carbon (¹³C NMR) spectra. Consequently, consolidated limits were determined for the integration of ¹H NMR spectra and ¹³C NMR of these samples using a statistical treatment applied to the limits of integration intervals already published. With these unified limits, correlation NMR charts were developed that are useful for the allocation of the integral at such intervals, and at smaller intervals defined in terms of the intersection between different assignments. Also raised equations needed to establish the integral attributable to specific fragments in an attempt to make a more accurate structural characterization from NMR spectra of oil, coal or fractions derived.

Keywords : structural characterization of coal and oil; nuclear magnetic resonance; integration of ¹H NMR and ¹³C NMR spectra; descriptive statistics.