Analytical
Liquid-State NMR Applications
Table
1 and Table 2
show the 1H and 13C functional group chemical shifts that
can be utilized to derive detailed molecular information on samples of interest
in the petroleum and petrochemical industries. Detailed molecular information
can be obtained from petroleum related samples such as crude
oils, base oils, diesels, bitumen, asphaltenes, naphthas.
Based on these particular chemical types that can be identified it is possible
to generate average molecular parameters that allow the effects of various
processes to be observed when the NMR parameters are compared for samples taken
before, during and after the desired processing. The following describe several
typical liquid state NMR applications that are routinely performed at PNA.
Crude
oil (including heavy oil) analysis
- detailed chemical breakdown obtained that
allows effects of various thermal and hydrothermal upgrading processes as well
as desulfurization to be followed by their effects on a series of detailed
average molecule parameters. Table
3 and Table 4
shows the detailed analysis parameters that can be obtained on crude oil samples
as well as all other petroleum products.
Petroleum
Product Analysis
- this
includes a large number of NMR interpretations on samples such as used
motor oils, lubricant oils, gasolines, diesel fuels, greases, waxes, gas oils,
recycled oils, fatty oils, vegetable oils, edible oils, etc.
Detailed chemical information as well as the quantity and type of contaminants
can be determined.
For
example, in used motor oils 31P NMR can be used to determine the
degradation of the
Zinc dithiophosphate anti-wear agents,
as well as the presence of
contaminants
originating in the gasoline (polyether, and PIB based additives) and
diesel fuel (heavy aromatics).
Lubricant
oil physical properties can be determined from the detailed chemistry observed
in the 13C and 1H NMR spectra.
Polymer
Characterization -
1H
and 13C NMR can be used effectively to determine the monomer ratio of
various mixed copolymers, the number average molecular weight, effectiveness of
hydrogenation, olefin analysis, molecular conformation, etc. Typical polymers
analyzed are PIB, PE, PP, mixed butene-ethylene, PVC, polystyrene, styrene
copolymers, EP copolymers, methacrylates, synthetic rubbers, polybutenes, PTFE,
nylons, etc.
Multinuclear
experiments -
various NMR active nuclei can be studied to
determine the chemical make-up of catalysts, polymers, and modified materials.
Nuclei commonly observed are 29Si, 31P, 19F, 27Al,
11B. Table 5 shows the
typical 29Si chemical shifts observed for siloxanes and silicates.
The structure and molecular weight of these materials can be readily obtained by
NMR.
Multidimensional
NMR Experiments -
Various specialized NMR experiments can be
used to determine the basic chemical functionality of a sample (DEPT), the
structural detail and connectivity (COSY, HETCOR), as well as the conformation
of a molecule (2D-3D NOE experiments). For example, COSY experiments can be used
to determine the conjugated diolefin content of gasolines and naphthas.
Unknown
Compound Structural Elucidation - Detailed
NMR experiments can be used in conjunction with sample isolation techniques to
allow identification of unknown compounds that are of interest in competitive
analysis reverse engineering, product marketing and field issues, customer
satisfaction issues, and environmental studies.
Reverse
Engineering of Polyurethane Adhesives
Analysis
of Naphtha by NMR
Use
of 13C NMR in Patents Related to Petroleum Products
1H
and 13C Type Analysis of Hydrocarbonic Solvents
13C
NMR of Biodiesel FAME
Incomplete
Transestrification - Partial Conversion of Vegetable Oil to Biodiesel
NMR
Analysis without Deuterated Solvents - Biodiesel and Glycerol Phase Analysis -
Methanol Quantification
Multidimensional
NMR of FAME - COSY and HETCOR
Wine
Analysis by 1H and 13C NMR - Acids Identification and
Quantification
Jasmine
Officinale - NMR Analysis
NMR
Analysis of Omega-3 Dietary Supplements
Aloe-Vera
Products by 1H and 13C NMR (Following IASC methodology)
Aromaticity,
Naphthenicity, and Paraffinicity of Hydrocarbons by 13C NMR
Detailed
Hydrocarbon Analysis by 1H and 13C NMR
Essential
Oil Analysis by 1H and 13C NMR - NMR Database Available
Polymorphism
by Solid-State NMR - Crystal Form and Crystalline/Amorphous Content
Determination
Conjugated
Diolefins Analysis by COSY
RCC
Feedstream Analysis - Correlation of Spectral and Calculated NMR Parameters with
Physico-Chemical Properties
1H
NMR Analysis of Hard Apple Cider
ASTM Methods of Hydrocarbon Testing
Correlated to Data From Laboratory-Based 1H and 13C NMR
Systems
Multidimensional NMR Spectroscopy -
COSY, HETCOR, HMQC, HMBC
Multinuclear NMR Studies - 29Si,
2H, 11B, 31P, 15N, 27Al, 23Na
..... in Liquid and Solid-State Systems.