Further NMR analysis and a few other experiments would allow some more detailed olefin chemistry distributions to be determined as well as observe the presence of conjugated diolefins that would be particularly troublesome in the processing of these materials.
The current CAPP method developed by the Canadian Crude Quality Technical Association (CCQTP) can be used to obtain total olefin content. We have developed many methods similar to this and have the ability to quantify and speciate the olefins present in the sample. The method is published at the following link. The method is particularly aimed at heavy oils and bitumens and their products that are not amenable to traditional olefin analysis. The Canadian Association of Petroleum Producers has produced a test method to quantify olefins in crude oils, condenates and diluents. The idea is to increase throughput by allowing extra acquisitions to be obtained on other samples during the relaxation delays of the independent experiments.An excellent video demonstration is available on the webpage dedicated to the probe, as well as references to the patent and the journal article covering the development (“Multiple-sample probe for solid-state NMR studies of pharmaceuticals”, Solid State Nuclear Magnetic Resonance 29 (2006), 204 – 213). The RF is switched between independent RF inputs and each housing has an independent tune/match capability. The concept involves stacking multiple MAS rotor housings in the probe head and then shuttling them into the central sweet spot of the magnet for acquisition via a pneumatic device attached at the base of the probe.
This is a probe based on a patent (6,937,020) filed by Professor Eric Munson’s NMR group at the University of Kansas, and built by David Lewis of Revolution NMR. I was at the SMASH conference in Burlington Vermont earlier this week and the presentation of the week in my opinion was the multi-sample MAS probe poster by Nelson et al.
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