Analytical Liquid-State Applications
Analytical liquid-state NMR experiments are performed on our two Varian Mercury-300 superconducting NMR spectrometer operating at 7.2 Tesla. These systems are equipped with multiple probes and are capable of performing most modern NMR experiments.
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.
Typical Liquid-State NMR Applications
We describe below typical Analytical 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 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 analysis 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.
Further Examples of NMR Analytical Liquid-State Analysis
- NMR Analysis of Polyurethanes
- Trans Fat Anaysis by 13C and 201H NMR
- Adulteration of Licorice by Maltodextrin – Liquid and Solid-State 1H/13C NMR Quantification
- Aloe Vera Analysis by Liquid and Solid-State NMR
- Acacia senegal adulteration with other regional gums – NMR analysis
- 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 F2259 – Alginate Analysis by 1H NMR – Mannuronate (M) and alpha-L-Guluronate (G)
- Balsamic Vinegar Analysis – Authentification and Ageing by 1H NMR
- 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.
- Reaction Monitoring 1H NMR in Permanent Magnet 60 MHz NMR systems
- Whole Leaf Marker and Maltodextrin – Dry Weight Quantification in Aloe Vera Raw Materials – Extended 1H NMR Method
- 60 MHz 1H Benchtop NMR of Trans-Fat, SAFA, PUFA, MONO in Edible Oils
- 300 MHz 1H Not-Benchtop Analysis of Trans-Fat, SAFA, PUFA, MONO in Edible Oils